Form N-Q

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, DC 20549

FORM N-Q


QUARTERLY SCHEDULE OF PORTFOLIO HOLDINGS OF REGISTERED MANAGEMENT INVESTMENT COMPANY

Investment Company Act file number         811-6548         

        Nuveen Select Tax-Free Income Portfolio         
(Exact name of registrant as specified in charter)

Nuveen Investments
        333 West Wacker Drive, Chicago, Illinois 60606         
(Address of principal executive offices) (Zip code)


Kevin J. McCarthy Vice President and Secretary
        333 West Wacker Drive, Chicago, Illinois 60606         
(Name and address of agent for service)

Registrant's telephone number, including area code:         312-917-7700        

Date of fiscal year end:            3/31          

Date of reporting period:         6/30/09         

Form N-Q is to be used by management investment companies, other than small business investment companies registered on Form N-5 (§§ 239.24 and 274.5 of this chapter), to file reports with the Commission, not later than 60 days after the close of the first and third fiscal quarters, pursuant to rule 30b1-5 under the Investment Company Act of 1940 (17 CFR 270.30b1-5). The Commission may use the information provided on Form N-Q in its regulatory, disclosure review, inspection, and policymaking roles.

A registrant is required to disclose the information specified by Form N-Q, and the Commission will make this information public. A registrant is not required to respond to the collection of information contained in Form N-Q unless the Form displays a currently valid Office of Management and Budget ("OMB") control number. Please direct comments concerning the accuracy of the information collection burden estimate and any suggestions for reducing the burden to the Secretary, Securities and Exchange Commission, 450 Fifth Street, NW, Washington, DC 20549-0609. The OMB has reviewed this collection of information under the clearance requirements of 44 U.S.C. § 3507.

Item 1. Schedule of Investments

    Portfolio of Investments (Unaudited)             
    Nuveen Select Tax-Free Income Portfolio (NXP)             
    June 30, 2009             
Principal        Optional Call         
Amount (000)    Description (1)    Provisions (2)    Ratings (3)    Value 
    Municipal Bonds – 99.1%             
    Alaska – 1.9%             
$       2,475    Alaska Municipal Bond Bank Authority, General Obligation Bonds, Series 2003E, 5.250%, 12/01/23    12/13 at 100.00    A+ (4)   $   2,837,390 
     (Pre-refunded 12/01/13) – MBIA Insured             
2,500    Northern Tobacco Securitization Corporation, Alaska, Tobacco Settlement Asset-Backed Bonds,    6/14 at 100.00    Baa3    1,361,500 
     Series 2006A, 5.000%, 6/01/46             
4,975    Total Alaska            4,198,890 
    Arkansas – 0.3%             
5,915    Arkansas Development Finance Authority, Tobacco Settlement Revenue Bonds, Arkansas Cancer    No Opt. Call    Aa3    690,872 
     Research Center Project, Series 2006, 0.000%, 7/01/46 – AMBAC Insured             
    California – 5.6%             
2,000    Alameda Corridor Transportation Authority, California, Subordinate Lien Revenue Bonds, Series    10/17 at 100.00    A–    1,466,560 
     2004A, 0.000%, 10/01/25 – AMBAC Insured             
3,325    California Department of Water Resources, Power Supply Revenue Bonds, Series 2002A,    5/12 at 101.00    Aa3    3,628,473 
     6.000%, 5/01/14             
1,000    California Statewide Community Development Authority, Revenue Bonds, Methodist Hospital    8/19 at 100.00    AA    1,037,680 
     Project, Series 2009, 6.750%, 2/01/38             
2,645    Cypress Elementary School District, San Bernardino County, California, General Obligation    No Opt. Call    AAA    528,154 
     Bonds, Series 2009A, 0.000%, 5/01/34 – FSA Insured             
3,000    Golden State Tobacco Securitization Corporation, California, Tobacco Settlement Asset-Backed    6/13 at 100.00    AAA    3,494,490 
     Bonds, Series 2003A-1, 6.750%, 6/01/39 (Pre-refunded 6/01/13)             
1,130    Los Angeles Department of Water and Power, California, Waterworks Revenue Refunding Bonds,    7/11 at 100.00    AA    1,087,896 
     Series 2001A, 5.125%, 7/01/41 – FGIC Insured             
365    Los Angeles, California, Parking System Revenue Bonds, Series 1999A, 5.250%, 5/01/29 –    5/10 at 100.00    A+    364,526 
     AMBAC Insured             
1,000    Moreno Valley Unified School District, Riverside County, California, General Obligation Bonds,    No Opt. Call    A    414,380 
     Series 2007, 0.000%, 8/01/23 – MBIA Insured             
750    Tobacco Securitization Authority of Northern California, Tobacco Settlement Asset-Backed    6/15 at 100.00    BBB    436,005 
     Bonds, Series 2005A-1, 5.500%, 6/01/45             
1,150    Woodside Elementary School District, San Mateo County, California, General Obligation Bonds,    No Opt. Call    AA+    274,137 
     Series 2007, 0.000%, 10/01/30 – AMBAC Insured             
16,365    Total California            12,732,301 
    Colorado – 11.9%             
1,700    Colorado Health Facilities Authority, Revenue Bonds, Catholic Health Initiatives, Series    3/12 at 100.00    AA (4)    1,853,170 
     2002A, 5.500%, 3/01/22 (ETM)             
690    Colorado Health Facilities Authority, Revenue Bonds, Catholic Health Initiatives, Series    3/12 at 100.00    AA (4)    762,802 
     2002A, 5.500%, 3/01/22 (Pre-refunded 3/01/12)             
390    Colorado Water Resources and Power Development Authority, Small Water Resources Revenue Bonds,    11/10 at 100.00    A    390,519 
     Series 2000A, 5.800%, 11/01/20 – FGIC Insured             
8,225    Denver City and County, Colorado, Airport System Revenue Bonds, Series 1991D, 7.750%, 11/15/13    No Opt. Call    A+    8,852,567 
     (Alternative Minimum Tax)             
5,000    Denver City and County, Colorado, Airport System Revenue Refunding Bonds, Series 2001A,    11/11 at 100.00    A+    5,078,550 
     5.625%, 11/15/17 – FGIC Insured (Alternative Minimum Tax)             
3,000    Denver Convention Center Hotel Authority, Colorado, Senior Revenue Bonds, Convention Center    12/13 at 100.00    N/R (4)    3,318,660 
     Hotel, Series 2003A, 5.000%, 12/01/23 (Pre-refunded 12/01/13) – SYNCORA GTY Insured             
500    Denver, Colorado, Airport System Revenue Refunding Bonds, Series 2003B, 5.000%, 11/15/33 –    11/13 at 100.00    A+    476,945 
     SYNCORA GTY Insured             
5,000    E-470 Public Highway Authority, Colorado, Senior Revenue Bonds, Series 2000B, 0.000%, 9/01/28    9/10 at 31.42    Aaa    1,550,050 
     (Pre-refunded 9/01/10) – MBIA Insured             
12,500    E-470 Public Highway Authority, Colorado, Toll Revenue Bonds, Series 2006A, 0.000%, 9/01/38 –    9/26 at 54.77    A    1,176,500 
     MBIA Insured             
3,160    Northwest Parkway Public Highway Authority, Colorado, Revenue Bonds, Senior Series 2001A,    6/11 at 102.00    N/R (4)    3,465,698 
     5.500%, 6/15/20 (Pre-refunded 6/15/11) – AMBAC Insured             
40,165    Total Colorado            26,925,461 
    District of Columbia – 0.1%             
60    District of Columbia, Revenue Bonds, Catholic University of America, Series 1999, 5.625%,    10/09 at 101.00    A    60,671 
     10/01/29 – AMBAC Insured             
205    District of Columbia, Revenue Bonds, Catholic University of America, Series 1999, 5.625%,    10/09 at 101.00    A (4)    209,619 
     10/01/29 (Pre-refunded 10/01/09) – AMBAC Insured             
265    Total District of Columbia            270,290 
    Florida – 7.5%             
2,000    Halifax Hospital Medical Center, Florida, Revenue Bonds, Series 2006, 5.375%, 6/01/46    6/16 at 100.00    A–    1,590,900 
5,000    Jacksonville Health Facilities Authority, Florida, Revenue Bonds, Ascension Health, Series    11/12 at 101.00    Aa1    5,009,350 
     2002A, 5.250%, 11/15/32             
10,000    JEA St. John’s River Power Park System, Florida, Revenue Refunding Bonds, Issue 2, Series    10/11 at 100.00    Aa2    10,191,199 
     2002-17, 5.000%, 10/01/17             
17,000    Total Florida            16,791,449 
    Hawaii – 0.6%             
1,330    Hawaii, Certificates of Participation, Kapolei State Office Building, Series 1998A, 5.000%,    11/09 at 100.50    N/R    1,346,359 
     5/01/17 – AMBAC Insured             
    Illinois – 13.3%             
1,965    Board of Trustees of Southern Illinois University, Housing and Auxiliary Facilities System    No Opt. Call    A1    1,184,895 
     Revenue Bonds, Series 1999A, 0.000%, 4/01/20 – MBIA Insured             
2,600    Chicago Heights, Illinois, General Obligation Corporate Purpose Bonds, Series 1993, 5.650%,    12/09 at 100.00    AA–    2,646,332 
     12/01/17 – FGIC Insured             
195    DuPage County Community School District 200, Wheaton, Illinois, General Obligation Bonds,    11/13 at 100.00    Aa3    207,753 
     Series 2003B, 5.250%, 11/01/20 – FSA Insured             
805    DuPage County Community School District 200, Wheaton, Illinois, General Obligation Bonds,    11/13 at 100.00    Aa3 (4)    914,842 
     Series 2003B, 5.250%, 11/01/20 (Pre-refunded 11/01/13) – FSA Insured             
600    Illinois Educational Facilities Authority, Student Housing Revenue Bonds, Educational    5/12 at 101.00    Aaa    683,226 
     Advancement Foundation Fund, University Center Project, Series 2002, 6.000%, 5/01/22             
     (Pre-refunded 5/01/12)             
1,050    Illinois Finance Authority, Revenue Bonds, Loyola University of Chicago, Tender Option Bond    7/17 at 100.00    Aa1    967,733 
     Trust 1137, 9.186%, 7/01/46 (IF)             
4,000    Illinois Finance Authority, Revenue Bonds, Northwestern Memorial Hospital, Series 2004A,    8/14 at 100.00    N/R (4)    4,628,560 
     5.500%, 8/15/43 (Pre-refunded 8/15/14)             
1,000    Illinois Finance Authority, Revenue Bonds, Silver Cross Hospital and Medical Centers, Series    8/19 at 100.00    BBB    965,210 
     2009, 6.875%, 8/15/38             
1,320    Illinois Health Facilities Authority, Revenue Bonds, Decatur Memorial Hospital, Series 2001,    10/11 at 100.00    A    1,330,138 
     5.600%, 10/01/16             
2,950    Illinois Health Facilities Authority, Revenue Bonds, Lake Forest Hospital, Series 2002A,    7/12 at 100.00    A–    3,014,841 
     6.000%, 7/01/17             
2,275    Illinois Health Facilities Authority, Revenue Refunding Bonds, Elmhurst Memorial Healthcare,    1/13 at 100.00    Baa1    2,302,732 
     Series 2002, 6.250%, 1/01/17             
75    Illinois Health Facilities Authority, Revenue Refunding Bonds, Rockford Health System, Series    8/09 at 100.00    N/R    66,406 
     1997, 5.000%, 8/15/21 – AMBAC Insured             
3,125    Metropolitan Pier and Exposition Authority, Illinois, Revenue Bonds, McCormick Place Expansion    No Opt. Call    A    2,213,594 
     Project, Series 1992A, 0.000%, 6/15/17 – FGIC Insured             
810    Metropolitan Pier and Exposition Authority, Illinois, Revenue Bonds, McCormick Place Expansion    No Opt. Call    AAA    229,910 
     Project, Series 2002A, 0.000%, 6/15/30 – MBIA Insured             
5,000    Metropolitan Pier and Exposition Authority, Illinois, Revenue Refunding Bonds, McCormick Place    6/12 at 101.00    AAA    5,144,000 
     Expansion Project, Series 2002B, 5.000%, 6/15/21 – MBIA Insured             
1,300    Schaumburg, Illinois, General Obligation Bonds, Series 2004B, 5.250%, 12/01/34 – FGIC Insured    12/14 at 100.00    AA+    1,314,586 
    Yorkville, Illinois, General Obligation Debt Certificates, Series 2003:             
1,000     5.000%, 12/15/19 (Pre-refunded 12/15/11) – RAAI Insured    12/11 at 100.00    BBB– (4)    1,096,170 
1,000     5.000%, 12/15/20 (Pre-refunded 12/15/11) – RAAI Insured    12/11 at 100.00    BBB– (4)    1,096,170 
31,070    Total Illinois            30,007,098 
    Indiana – 7.1%             
1,000    Franklin Community Multi-School Building Corporation, Marion County, Indiana, First Mortgage    7/14 at 100.00    A (4)    1,140,350 
     Revenue Bonds, Series 2004, 5.000%, 7/15/22 (Pre-refunded 7/15/14) – FGIC Insured             
2,000    Indiana Health Facility Financing Authority, Hospital Revenue Refunding Bonds, Columbus    No Opt. Call    AAA    2,270,560 
     Regional Hospital, Series 1993, 7.000%, 8/15/15 – FSA Insured             
1,000    Indiana Health Facility Financing Authority, Revenue Bonds, Community Foundation of Northwest    3/17 at 100.00    BBB    853,040 
     Indiana, Series 2007, 5.500%, 3/01/37             
9,855    Indianapolis Local Public Improvement Bond Bank, Indiana, Waterworks Project, Series 2002A,    7/12 at 100.00    AAA    10,947,721 
     5.125%, 7/01/21 (Pre-refunded 7/01/12) – MBIA Insured             
750    West Clark 2000 School Building Corporation, Clark County, Indiana, First Mortgage Bonds,    1/15 at 100.00    AA+    780,053 
     Series 2005, 5.000%, 7/15/22 – MBIA Insured             
14,605    Total Indiana            15,991,724 
    Iowa – 1.6%             
1,000    Iowa Tobacco Settlement Authority, Asset Backed Settlement Revenue Bonds, Series 2005C,    6/15 at 100.00    BBB    595,350 
     5.375%, 6/01/38             
4,000    Iowa Tobacco Settlement Authority, Tobacco Asset-Backed Revenue Bonds, Series 2005B,    6/17 at 100.00    BBB    2,935,800 
     5.600%, 6/01/34             
5,000    Total Iowa            3,531,150 
    Kansas – 0.5%             
500    Lawrence, Kansas, Hospital Revenue Bonds, Lawrence Memorial Hospital, Series 2006,    7/16 at 100.00    A3    402,055 
     4.875%, 7/01/36             
750    Wamego, Kansas, Pollution Control Revenue Bonds, Kansas Gas and Electric Company, Series 2004,    6/14 at 100.00    A    726,353 
     5.300%, 6/01/31 – MBIA Insured             
1,250    Total Kansas            1,128,408 
    Kentucky – 0.5%             
1,100    Jefferson County, Kentucky, Health System Revenue Bonds, Alliant Health System Inc., Series    10/09 at 100.50    A (4)    1,114,124 
     1998, 5.125%, 10/01/18 – MBIA Insured (ETM)             
    Louisiana – 0.4%             
1,100    Tobacco Settlement Financing Corporation, Louisiana, Tobacco Settlement Asset-Backed Bonds,    5/11 at 101.00    BBB    866,459 
     Series 2001B, 5.875%, 5/15/39             
    Massachusetts – 2.0%             
500    Massachusetts Health and Educational Facilities Authority, Revenue Bonds, CareGroup Inc.,    7/18 at 100.00    A3    449,520 
     Series 2008E-1, 5.000%, 7/01/28             
20    Massachusetts Health and Educational Facilities Authority, Revenue Bonds, Partners HealthCare    7/11 at 101.00    AA    21,470 
     System Inc., Series 2001C, 6.000%, 7/01/17             
480    Massachusetts Health and Educational Facilities Authority, Revenue Bonds, Partners HealthCare    7/11 at 101.00    AAA    532,330 
     System Inc., Series 2001C, 6.000%, 7/01/17 (Pre-refunded 7/01/11)             
2,000    Massachusetts Housing Finance Agency, Housing Bonds, Series 2009F, 5.700%, 6/01/40    12/18 at 100.00    AA–    1,907,880 
1,055    Massachusetts Turnpike Authority, Metropolitan Highway System Revenue Bonds, Senior Series    7/09 at 100.00    AA–    869,721 
     1997A, 5.000%, 1/01/37 – MBIA Insured             
830    Massachusetts Turnpike Authority, Metropolitan Highway System Revenue Bonds, Subordinate    7/09 at 101.00    BBB    678,616 
     Series 1999A, 5.000%, 1/01/39 – AMBAC Insured             
4,885    Total Massachusetts            4,459,537 
    Michigan – 1.6%             
1,000    Michigan State Hospital Finance Authority, Hospital Revenue Bonds, Detroit Medical Center    8/09 at 100.00    BB–    784,190 
     Obligated Group, Series 1998A, 5.125%, 8/15/18             
2,900    Michigan State Hospital Finance Authority, Hospital Revenue Refunding Bonds, Trinity Health    12/12 at 100.00    AA    2,872,566 
     Credit Group, Series 2002C, 5.375%, 12/01/30             
3,900    Total Michigan            3,656,756 
    Minnesota – 0.1%             
220    Minnesota Housing Finance Agency, Single Family Mortgage Revenue Bonds, Series 1995A,    7/09 at 100.50    AA+    221,956 
     5.200%, 1/01/17             
    Missouri – 0.7%             
5,000    Kansas City Municipal Assistance Corporation, Missouri, Leasehold Revenue Bonds, Series    No Opt. Call    AA–    1,584,250 
     2004B-1, 0.000%, 4/15/30 – AMBAC Insured             
    Nevada – 4.9%             
2,500    Clark County, Nevada, Motor Vehicle Fuel Tax Highway Improvement Revenue Bonds, Series 2003,    7/13 at 100.00    AA–    2,480,125 
     5.000%, 7/01/23 – AMBAC Insured             
    Director of Nevada State Department of Business and Industry, Revenue Bonds, Las Vegas             
    Monorail Project, First Tier, Series 2000:             
2,360     0.000%, 1/01/21 – AMBAC Insured    No Opt. Call    BBB    346,354 
4,070     0.000%, 1/01/22 – AMBAC Insured    No Opt. Call    BBB    553,642 
6,025     5.375%, 1/01/40 – AMBAC Insured    1/10 at 100.00    BBB    1,864,497 
1,500    Las Vegas Redevelopment Agency, Nevada, Tax Increment Revenue Bonds, Series 2009A,    6/19 at 100.00    A    1,577,655 
     8.000%, 6/15/30             
1,515    Reno, Nevada, Capital Improvement Revenue Bonds, Series 2002, 5.500%, 6/01/21 – FGIC Insured    6/12 at 100.00    A    1,408,026 
2,555    Reno, Nevada, Capital Improvement Revenue Bonds, Series 2002, 5.500%, 6/01/21 (Pre-refunded    6/12 at 100.00    Baa1 (4)    2,855,545 
     6/01/12) – FGIC Insured             
20,525    Total Nevada            11,085,844 
    New Hampshire – 0.2%             
380    New Hampshire Housing Finance Authority, Single Family Mortgage Acquisition Bonds, Series    5/11 at 100.00    Aa2    376,044 
     2001A, 5.600%, 7/01/21 (Alternative Minimum Tax)             
    New Jersey – 2.5%             
2,500    New Jersey Health Care Facilities Financing Authority, Revenue Bonds, Somerset Medical Center,    7/13 at 100.00    Ba2    1,643,050 
     Series 2003, 5.500%, 7/01/23             
    Tobacco Settlement Financing Corporation, New Jersey, Tobacco Settlement Asset-Backed Bonds,             
    Series 2002:             
1,325     5.750%, 6/01/32 (Pre-refunded 6/01/12)    6/12 at 100.00    AAA    1,444,701 
1,000     6.000%, 6/01/37 (Pre-refunded 6/01/12)    6/12 at 100.00    AAA    1,136,520 
2,500    Tobacco Settlement Financing Corporation, New Jersey, Tobacco Settlement Asset-Backed Bonds,    6/17 at 100.00    BBB    1,367,850 
     Series 2007-1A, 5.000%, 6/01/41             
7,325    Total New Jersey            5,592,121 
    New Mexico – 2.1%             
1,000    New Mexico Mortgage Finance Authority, Multifamily Housing Revenue Bonds, St Anthony, Series    9/17 at 100.00    AAA    924,840 
     2007A, 5.250%, 9/01/42 (Alternative Minimum Tax)             
4,000    University of New Mexico, FHA-Insured Mortgage Hospital Revenue Bonds, Series 2004, 4.625%,    7/14 at 100.00    AAA    3,738,560 
     7/01/25 – FSA Insured             
5,000    Total New Mexico            4,663,400 
    New York – 1.2%             
1,000    Dormitory Authority of the State of New York, FHA-Insured Mortgage Revenue Bonds, Kaleida    2/14 at 100.00    AAA    1,020,010 
     Health, Series 2004, 5.050%, 2/15/25             
1,215    Dormitory Authority of the State of New York, Revenue Bonds, Mount Sinai NYU Health Obligated    7/10 at 101.00    A3    1,250,551 
     Group, Series 2000A, 6.500%, 7/01/17             
385    Dormitory Authority of the State of New York, Revenue Bonds, Mount Sinai NYU Health Obligated    7/10 at 101.00    A3 (4)    409,182 
     Group, Series 2000A, 6.500%, 7/01/17 (Pre-refunded 7/01/10)             
2,600    Total New York            2,679,743 
    North Carolina – 1.7%             
1,000    North Carolina Eastern Municipal Power Agency, Power System Revenue Bonds, Series 2008C,    1/19 at 100.00    BBB+    1,104,800 
     6.750%, 1/01/24             
2,195    North Carolina Eastern Municipal Power Agency, Power System Revenue Refunding Bonds, Series    7/09 at 100.00    BBB+    2,195,439 
     1993B, 5.500%, 1/01/21             
500    Raleigh Durham Airport Authority, North Carolina, Airport Revenue Bonds, Series 2001A, 5.250%,    5/11 at 101.00    Aa3    513,680 
     11/01/17 – FGIC Insured             
3,695    Total North Carolina            3,813,919 
    Ohio – 0.5%             
1,500    Buckeye Tobacco Settlement Financing Authority, Ohio, Tobacco Settlement Asset-Backed Revenue    6/17 at 100.00    BBB    891,285 
     Bonds, Senior Lien, Series 2007A-2, 6.000%, 6/01/42             
300    Lebanon, Ohio, Electric System Mortgage Revenue Bonds, Series 2001, 5.500%, 12/01/17    12/10 at 101.00    A2 (4)    323,664 
     (Pre-refunded 12/01/10) – AMBAC Insured             
1,800    Total Ohio            1,214,949 
    Oklahoma – 2.0%             
1,000    Norman Regional Hospital Authority, Oklahoma, Hospital Revenue Bonds, Series 2005,    9/16 at 100.00    BBB–    678,650 
     5.375%, 9/01/36             
4,000    Oklahoma Development Finance Authority, Revenue Bonds, St. John Health System, Series 2004,    2/14 at 100.00    A    3,819,920 
     5.000%, 2/15/24             
5,000    Total Oklahoma            4,498,570 
    Pennsylvania – 0.8%             
500    Pennsylvania Higher Educational Facilities Authority, Revenue Bonds, Widener University,    7/13 at 100.00    BBB+    443,645 
     Series 2003, 5.250%, 7/15/24             
700    Pennsylvania Turnpike Commission, Turnpike Revenue Bonds, Series 2004A, 5.500%, 12/01/31 –    12/14 at 100.00    Aa3    711,424 
     AMBAC Insured             
520    Pennsylvania, General Obligation Bonds, Second Series 2001, 5.000%, 9/15/20 (Pre-refunded    9/11 at 101.00    AAA    570,492 
     9/15/11) – FSA Insured             
1,720    Total Pennsylvania            1,725,561 
    Puerto Rico – 0.4%             
1,000    Puerto Rico Sales Tax Financing Corporation, Sales Tax Revenue Bonds, First Subordinate Series    8/19 at 100.00    A+    980,220 
     2009A, 6.000%, 8/01/42             
    South Carolina – 8.1%             
1,250    Dorchester County School District 2, South Carolina, Installment Purchase Revenue Bonds,    12/14 at 100.00    AA–    1,287,750 
     GROWTH, Series 2004, 5.250%, 12/01/20             
10,000    Greenville County School District, South Carolina, Installment Purchase Revenue Bonds, Series    12/12 at 101.00    AA (4)    11,604,396 
     2002, 5.875%, 12/01/19 (Pre-refunded 12/01/12)             
1,500    Lexington County Health Service District, South Carolina, Hospital Revenue Refunding and    11/13 at 100.00    A+ (4)    1,752,600 
     Improvement Bonds, Series 2003, 6.000%, 11/01/18 (Pre-refunded 11/01/13)             
520    South Carolina JOBS Economic Development Authority, Economic Development Revenue Bonds, Bon    11/12 at 100.00    A3 (4)    591,063 
     Secours Health System Inc., Series 2002A, 5.625%, 11/15/30 (Pre-refunded 11/15/12)             
1,980    South Carolina JOBS Economic Development Authority, Economic Development Revenue Bonds, Bon    11/12 at 100.00    A–    1,832,767 
     Secours Health System Inc., Series 2002B, 5.625%, 11/15/30             
1,130    Tobacco Settlement Revenue Management Authority, South Carolina, Tobacco Settlement    5/12 at 100.00    BBB (4)    1,191,201 
     Asset-Backed Bonds, Series 2001B, 6.000%, 5/15/22 (Pre-refunded 5/15/12)             
16,380    Total South Carolina            18,259,777 
    Texas – 8.2%             
5,000    Brazos River Harbor Navigation District, Brazoria County, Texas, Environmental Facilities    5/12 at 101.00    BBB–    4,651,050 
     Revenue Bonds, Dow Chemical Company Project, Series 2002A-6, 6.250%, 5/15/33 (Mandatory             
     put 5/15/17) (Alternative Minimum Tax)             
1,000    Dallas Area Rapid Transit, Texas, Senior Lien Sales Tax Revenue Bonds, Series 2001, 5.000%,    12/11 at 100.00    AAA    1,095,320 
     12/01/31 (Pre-refunded 12/01/11) – AMBAC Insured             
360    Dallas-Fort Worth International Airport Public Facility Corporation, Texas, Airport Hotel    7/09 at 100.00    AAA    360,151 
     Revenue Bonds, Series 2001, 5.500%, 1/15/20 – FSA Insured             
2,300    Harris County Health Facilities Development Corporation, Texas, Thermal Utility Revenue Bonds,    11/13 at 100.00    AA–    2,220,788 
     TECO Project, Series 2003, 5.000%, 11/15/30 – MBIA Insured             
1,550    Harris County-Houston Sports Authority, Texas, Junior Lien Revenue Bonds, Series 2001H,    No Opt. Call    A    307,660 
     0.000%, 11/15/30 – MBIA Insured             
3,470    Harris County-Houston Sports Authority, Texas, Senior Lien Revenue Refunding Bonds, Series    11/30 at 61.17    A    359,388 
     2001A, 0.000%, 11/15/38 – MBIA Insured             
2,805    Harris County-Houston Sports Authority, Texas, Third Lien Revenue Bonds, Series 2004-A3.,    11/24 at 52.47    A    354,356 
     0.000%, 11/15/35 – MBIA Insured             
45    Irving Independent School District, Dallas County, Texas, General Obligation Refunding Bonds,    2/12 at 100.00    AAA    45,305 
     Series 2002A, 5.000%, 2/15/31             
3,455    Irving Independent School District, Dallas County, Texas, General Obligation Refunding Bonds,    2/12 at 100.00    AAA    3,789,444 
     Series 2002A, 5.000%, 2/15/31 (Pre-refunded 2/15/12)             
1,780    Leander Independent School District, Williamson and Travis Counties, Texas, General Obligation    8/16 at 35.23    AAA    341,440 
     Bonds, Series 2007, 0.000%, 8/15/37             
2,000    North Texas Thruway Authority, First Tier System Revenue Refunding Bonds, Capital Appreciation    1/25 at 100.00    A2    1,366,020 
     Series 2008I, 0.000%, 1/01/43             
2,000    Richardson Hospital Authority, Texas, Revenue Bonds, Richardson Regional Medical Center,    12/13 at 100.00    Baa2    1,518,300 
     Series 2004, 6.000%, 12/01/34             
465    San Antonio, Texas, Water System Revenue Refunding Bonds, Series 1992, 6.000%, 5/15/16    5/12 at 100.00    Aa3 (4)    527,105 
     (Pre-refunded 5/15/12) – MBIA Insured             
1,750    Texas, General Obligation Bonds, Water Financial Assistance Program, Series 2003A, 5.125%,    8/13 at 100.00    Aa1    1,529,658 
     8/01/42 (Alternative Minimum Tax)             
27,980    Total Texas            18,465,985 
    Utah – 0.4%             
775    Utah State Building Ownership Authority, Lease Revenue Bonds, State Facilities Master Lease    11/11 at 100.00    AA+    806,519 
     Program, Series 2001B, 5.250%, 5/15/24             
    Virginia – 0.5%             
1,500    Fairfax County Economic Development Authority, Virginia, Residential Care Facilities Mortgage    10/17 at 100.00    N/R    1,113,120 
     Revenue Bonds, Goodwin House, Inc., Series 2007A, 5.125%, 10/01/42             
    Washington – 7.5%             
250    Energy Northwest, Washington, Electric Revenue Refunding Bonds, Columbia Generating Station –    7/12 at 100.00    Aaa    270,813 
     Nuclear Project 2, Series 2002C, 5.500%, 7/01/17 – MBIA Insured             
3,610    Snohomish County Public Utility District 1, Washington, Generation System Revenue Bonds,    No Opt. Call    Aaa    3,880,100 
     Series 1989, 6.750%, 1/01/12 (ETM)             
9,750    Washington State Healthcare Facilities Authority, Revenue Bonds, Sisters of Providence Health    10/11 at 100.00    AA    9,914,677 
     System, Series 2001A, 5.125%, 10/01/17 – MBIA Insured             
2,105    Washington State Tobacco Settlement Authority, Tobacco Settlement Asset-Backed Revenue Bonds,    6/13 at 100.00    BBB    2,087,823 
     Series 2002, 6.500%, 6/01/26             
2,115    Washington State, Motor Vehicle Fuel Tax General Obligation Bonds, Series 2003F, 0.000%,    No Opt. Call    AA+    817,173 
     12/01/27 – MBIA Insured             
17,830    Total Washington            16,970,586 
    West Virginia – 0.5%             
760    Marshall County, West Virginia, Special Obligation Refunding Bonds, Series 1992, 6.500%,    No Opt. Call    AAA    793,197 
     5/15/10 (ETM)             
500    West Virginia Hospital Finance Authority, Revenue Bonds, United Hospital Center Inc. Project,    6/16 at 100.00    A+    434,405 
     Series 2006A, 4.500%, 6/01/26 – AMBAC Insured             
1,260    Total West Virginia            1,227,602 
    Wisconsin – 1.9%             
785    Badger Tobacco Asset Securitization Corporation, Wisconsin, Tobacco Settlement Asset-Backed    6/12 at 100.00    AAA    853,334 
     Bonds, Series 2002, 6.125%, 6/01/27 (Pre-refunded 6/01/12)             
1,000    Wisconsin Health and Educational Facilities Authority, Revenue Bonds, Wheaton Franciscan    8/13 at 100.00    BBB+    950,870 
     Services Inc., Series 2003A, 5.500%, 8/15/17             
2,500    Wisconsin, General Obligation Refunding Bonds, Series 2003-3, 5.000%, 11/01/26    11/13 at 100.00    AA    2,548,600 
4,285    Total Wisconsin            4,352,804 
$   273,200    Total Municipal Bonds (cost $227,039,901)            223,343,848 
Shares    Description (1)            Value 
    Common Stocks – 0.0%             
    Airlines – 0.0%             
789    UAL Corporation, (5)          $  2,517 
    Total Common Stocks (cost $0)            2,517 
    Total Investments (cost $227,039,901) – 99.1%            223,346,365 
    Other Assets Less Liabilities – 0.9%            1,923,354 
    Net Assets – 100%          $  225,269,719 

Fair Value Measurements

In determining the value of the Fund's investments various inputs are used. These inputs are summarized in the three broad levels listed below:

Level 1 – Quoted prices in active markets for identical securities.

Level 2 – Other significant observable inputs (including quoted prices for similar securities, interest rates, prepayment speeds, credit risk, etc.).

Level 3 – Significant unobservable inputs (including management's assumptions in determining the fair value of investments).

The inputs or methodology used for valuing securities are not an indication of the risk associated with investing in those securities.

The following is a summary of the Fund's fair value measurements as of June 30, 2009:

    Level 1    Level 2    Level 3    Total 
Investments:                 
   Municipal Bonds    $     —    $223,343,848    $ —    $223,343,848 
   Common Stocks    2,517    —    —    2,517 
Total    $2,517    $223,343,848    $ —    $223,346,365 

Income Tax Information

The following information is presented on an income tax basis. Differences between amounts for financial statement and federal income tax purposes are primarily due to timing differences in recognizing taxable market discount, timing differences in recognizing certain gains and losses on investment transactions and the treatment of investments in inverse floating rate transactions subject to Statement of Financial Accounting Standards No. 140 (SFAS No. 140), if any. To the extent that differences arise that are permanent in nature, such amounts are reclassified within the capital accounts on the Statement of Assets and Liabilities presented in the annual report, based on their federal tax basis treatment; temporary differences do not require reclassification. Temporary and permanent differences do not impact the net asset values of the Fund.

At June 30, 2009, the cost of investments was $226,734,326.

Gross unrealized appreciation and gross unrealized depreciation of investments at June 30, 2009, were as follows:

Gross unrealized:     
  Appreciation    $ 12,153,013 
  Depreciation    (15,540,974)
Net unrealized appreciation (depreciation) of investments    $  (3,387,961)

(1)    All percentages shown in the Portfolio of Investments are based on net assets. 
(2)    Optional Call Provisions: Dates (month and year) and prices of the earliest optional call or redemption. 
    There may be other call provisions at varying prices at later dates. Certain mortgage-backed securities 
    may be subject to periodic principal paydowns. 
(3)    Ratings: Using the higher of Standard & Poor's Group ("Standard & Poor's") or Moody's Investor Service, 
    Inc. ("Moody's") rating. Ratings below BBB by Standard & Poor's or Baa by Moody's are considered to 
    be below investment grade. 
(4)    Backed by an escrow or trust containing sufficient U.S. Government or U.S. Government agency 
    securities which ensure the timely payment of principal and interest. Such investments are normally 
    considered to be equivalent to AAA rated securities. 
(5)    On December 9, 2002, UAL Corporation (“UAL”), the holding company of United Air Lines, Inc. (“United”) 
    filed for federal bankruptcy protection. The Adviser determined that it was likely that United would not 
    remain current on their interest payment obligations with respect to the bonds previously held and thus 
    the Fund had stopped accruing interest on its UAL bonds. On February 1, 2006, UAL emerged from 
    federal bankruptcy with the acceptance of its reorganization plan by the bankruptcy court. Under the 
    settlement agreement established to meet UAL’s unsecured bond obligations, the bondholders, including 
    the Fund, received three distributions of UAL common stock over the subsequent months, and the 
    bankruptcy court dismissed all unsecured claims of bondholders, including those of the Fund. On May 5, 
    2006, the Fund liquidated such UAL common stock holdings. On September 29, 2006 and May 30, 2007, 
    the Fund received additional distributions of 1,901 and 617 shares, respectively, of UAL common stock as 
    a result of its earlier ownership of the UAL bonds. The Fund liquidated 1,901 shares of such UAL common 
    stock holdings on November 15, 2006. The Fund received an additional distribution of 172 UAL common 
    stock shares on November 14, 2007. The remaining 789 shares of UAL common stock were still held by 
    the Fund at June 30, 2009. 
N/R    Not rated. 
(ETM)    Escrowed to maturity. 
(IF)    Inverse floating rate investment. 

Item 2. Controls and Procedures.

  1. The registrant's principal executive and principal financial officers, or persons performing similar functions, have concluded that the registrant's disclosure controls and procedures (as defined in Rule 30a-3(c) under the Investment Company Act of 1940, as amended (the "1940 Act") (17 CFR 270.30a-3(c))) are effective, as of a date within 90 days of the filing date of this report that includes the disclosure required by this paragraph, based on their evaluation of the controls and procedures required by Rule 30a-3(b) under the 1940 Act (17 CFR 270.30a-3(b)) and Rule 13a-15(b) or 15d-15(b) under the Securities Exchange Act of 1934 (17 CFR 240.13a-15(b) or 240.15d-15(b)).
  2. There were no changes in the registrant's internal control over financial reporting (as defined in Rule 30a-3(d) under the 1940 Act (17 CFR 270.30a-3(d)) that occurred during the registrant's last fiscal quarter that have materially affected, or are reasonably likely to materially affect, the registrant's internal control over financial reporting.

Item 3. Exhibits.

File as exhibits as part of this Form a separate certification for each principal executive officer and principal financial officer of the registrant as required by Rule 30a-2(a) under the 1940 Act (17 CFR 270.30a-2(a)), exactly as set forth below: See EX-99 CERT attached hereto.


SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

(Registrant)         Nuveen Select Tax-Free Income Portfolio         

By (Signature and Title)          /s/ Kevin J. McCarthy                    
                                                  Kevin J. McCarthy
                                                  Vice President and Secretary

Date         August 28, 2009        

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, this report has been signed below by the following persons on behalf of the registrant and in the capacities and on the dates indicated.

By (Signature and Title)         /s/ Gifford R. Zimmerman                    
                                                 Gifford R. Zimmerman
                                                 Chief Administrative Officer (principal executive officer) 

Date         August 28, 2009        

By (Signature and Title)         /s/ Stephen D. Foy                              
                                                 Stephen D. Foy
                                                 Vice President and Controller (principal financial officer) 

Date        August 28, 2009