As filed with the Securities and Exchange Commission on May 30, 2003
                                                  Registration No. 333- ________
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                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                            -------------------------

                                    FORM S-8
                          REGISTRATION STATEMENT UNDER
                           THE SECURITIES ACT OF 1933

                            -------------------------

                           KNIGHT TRANSPORTATION, INC.
             (Exact name of Registrant as specified in its charter)

                 ARIZONA                                 86-0649974
                 (State)                    (I.R.S. Employer Identification No.)

           5601 W. BUCKEYE RD.
            PHOENIX, ARIZONA                               85043
(Address of Principal Executive Offices)                 (Zip Code)

                        2003 KNIGHT TRANSPORTATION, INC.
                                STOCK OPTION PLAN
                            (Full title of the plan)

                            -------------------------

                                  With copy to:
      Kevin P. Knight                                 James E. Brophy, III, Esq.
  Chief Executive Officer                             Ryley Carlock & Applewhite
Knight Transportation, Inc.                                   Suite 1200
  5601 West Buckeye Road                               One North Central Avenue
  Phoenix, Arizona 85043                                Phoenix, Arizona 85004
      (602) 269-2000                                        (602) 258-7701
            (Name, address and telephone number of agent for service)

                            -------------------------

                         CALCULATION OF REGISTRATION FEE


======================================================================================================
                                            Proposed maximum    Proposed maximum
Title of securities to be   Amount to be   offering price per  aggregate offering       Amount of
registered                 registered (1)       share (2)          price (2)       registration fee(3)
------------------------------------------------------------------------------------------------------
                                                                           
Common stock, par value
  $.01 per share             1,000,000           $24.50           $24,500,000          $1,559.00
======================================================================================================

(1)  There are also  registered an undetermined  number of additional  shares of
     the  Company's  Common Stock that may become  issuable  under the Company's
     2003 Stock Option Plan in the event of certain  changes in the  outstanding
     shares of the  Company's  Common  Stock or in the capital  structure of the
     Company,  including any stock dividend,  stock split,  recapitalization  or
     similar transaction.
(2)  Estimated  solely for the  purpose of  calculating  the  registration  fee,
     pursuant to Rule 457(c) and 457(h) of the  Securities  Act of 1933,  on the
     basis of the  average  of the high and low prices of the  Company's  Common
     Stock on the National  Association of Securities  Dealers  Automated System
     (National Market) on May 28, 2003 as reported by the NASDAQ Stock Market.
(3)  The  registration  fee was calculated as the  difference  between the total
     computed fee of $1,982 less the sum of $423.00 that was previously  paid in
     connection with Form S-8 Registration  Statement File No. 333-72377,  filed
     on February 12, 1999. The Company has filed a  post-effective  amendment to
     its Form  S-8  Registration  Statement  File No.  333-72377  to  deregister
     471,187  shares of the  Company's  Common  Stock  that are not  subject  to
     outstanding  option grants under its 1998 Amended and Restated Stock Option
     Plan.

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                                     PART I

              INFORMATION REQUIRED IN THE SECTION 10(A) PROSPECTUS

     The documents  containing the information  specified in Part I, Items 1 and
2, will be delivered  to each  employee  who is eligible to  participate  in the
Knight  Transportation,  Inc. 2003 Stock Option Plan (the "Plan"), in accordance
with Form S-8 and Securities Act Rule 428(b)(1).

                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3: INCORPORATION OF DOCUMENTS BY REFERENCE.

     The following  documents  previously filed with the Securities and Exchange
Commission  (the  "Commission")  are hereby  incorporated by reference into this
Registration Statement:

     a. The  Company's  Annual  Report on Form 10-K for the  fiscal  year  ended
December 31, 2002.

     b. All other  reports  filed by the Company  pursuant  to Section  13(a) or
15(d) of the Securities Exchange Act of 1934 since December 31, 2002.

     c. Description of Common Stock set forth in the Company's  Prospectus dated
July 19, 1996, filed as part of the Company's Registration Statement on Form S-1
with File Number 3383534.

     All documents subsequently filed by the Company pursuant to Sections 13(a),
13(c), 14 and 15(d) of the Securities  Exchange Act of 1934, prior to the filing
of a post-effective amendment which indicates that all securities of the Company
offered through the Plan have been sold or which deregisters all securities then
remaining  unsold,  shall be  deemed to be  incorporated  by  reference  in this
Registration  Statement  and to be a part hereof from the date of filing of such
documents.

ITEM 4: DESCRIPTION OF SECURITIES.

     Not applicable.

ITEM 5: INTERESTS OF NAMED EXPERTS AND COUNSEL.

     Not applicable.

                                       -2-

ITEM 6: INDEMNIFICATION OF DIRECTORS AND OFFICERS.

     Arizona Revised  Statutes Section 10-851 permits a corporation to indemnify
an  individual  made a party to a proceeding  if (i) the  individual is or was a
director of the  corporation,  the  individual's  conduct was in good faith, the
individual  reasonably  believed that the conduct was in the corporation's  best
interests,  and, if a criminal action, the individual had no reasonable cause to
believe the conduct was unlawful,  and (ii) the director  engaged in conduct for
which broader  indemnification  has been made permissible  under a corporation's
Articles of Incorporation.  Arizona Revised Statutes Section 10-855 prohibits an
Arizona corporation from indemnifying a director until after a determination has
been made that  indemnification is permissible  because the director has met the
requisite standard of conduct.  This determination must be made by a majority of
the corporation's board of directors,  other than those directors that are party
to the proceeding; by special legal counsel; or by the shareholders,  other than
the director that is a party to the proceeding, if such director owns shares.

     Arizona Revised Statutes Section 10-852 requires a corporation to indemnify
a director  who is the  prevailing  party,  on the merits or  otherwise,  in the
defense of any proceeding to which the director was a party because the director
is or was a director  of the  corporation,  unless  limited  by a  corporation's
articles of  incorporation.  Section  10-852 of Arizona  Revised  Statutes  also
requires a  corporation  to indemnify  an outside  director  against  liability,
unless the corporation's  articles of incorporation  provide  otherwise.  Unless
limited by a corporation's  articles of  incorporation,  an Arizona  corporation
shall pay an outside director's  expenses in advance of a final disposition of a
proceeding if the director  gives the  corporation a written  affirmation of the
director's  good faith  belief that the director has met the standard of conduct
described in Section  10-851,  and the director gives the  corporation a written
undertaking  to repay the advance if it is determined  the director did not meet
the requisite standard of conduct.

     Arizona Revised Statutes  Section 10-856 permits an Arizona  corporation to
indemnify  officers  that are  party to a  proceeding  to the same  extent  as a
director  under  Section  10-851  and as  further  provided  in a  corporation's
articles of incorporation,  except for (i) an officer's  liability in connection
with a  proceeding  by or in  the  right  of the  corporation,  other  than  for
reasonable expenses incurred,  or (ii) liability that constitutes receipt by the
officer  of a  financial  benefit  to which the  officer  was not  entitled,  an
intentional  infliction of harm on the  corporation or its  shareholders,  or an
intentional violation of a criminal law.

Article XIII of the Company's Restated Articles of Incorporation states:

     "The corporation shall indemnify and hold harmless its  incorporators,  and
each of its existing and former directors,  to the fullest extent not prohibited
by law, as it now exists or may  hereafter  be amended,  for any and all acts or
omissions  done or omitted to be done while employed by, or acting on behalf of,
the  Corporation  or its  subsidiaries,  including  indemnity for service in the
capacity  as an  officer  of the  Corporation.  The  Corporation,  subject  to a
director  executing and delivering any undertaking  required by law to reimburse
the  Corporation  if indemnity  should not be allowed,  shall  advance costs and

                                       -3-

expenses to defend any claim subject to  indemnification.  Without  limiting the
foregoing,  a director shall not be personally  liable to the Corporation or its
shareholders  for monetary  damages for breach of fiduciary  duty as a director,
except  as  otherwise  provided  by law;  provided  that no  provision  of these
Articles of  Incorporation  shall eliminate or limit the liability of a director
for (i) any breach of a  director's  duty of loyalty to the  corporation  or its
shareholders,  (ii)  acts or  omissions  which  are not in good  faith  or which
involve intentional  misconduct or a knowing violation of law, (iii) authorizing
the unlawful  payment of a dividend or other  distribution on the  Corporation's
common  capital stock or the unlawful  purchase of its capital  stock,  (iv) any
transaction from which a director received an improper personal benefit,  or (v)
any  violation  of  Section  10-041  of the  Arizona  Revised  Statutes,  or any
successor provisions thereto.  The indemnification  rights provided herein shall
not be exclusive of or preclude any other rights of  indemnification  to which a
director,  officer, employee or agent may be entitled,  whether pursuant to law,
bylaws or agreement."

Section 7 of the Company's Amended and Restated Bylaws states:

     "The corporation  shall indemnify and save harmless all of its existing and
former directors from and against all expenses incurred by them, including,  but
not limited to, legal fees, judgments, penalties, and amounts paid in settlement
or compromise,  to the fullest extent not prohibited by law, as it now exists or
may  hereafter  be  amended,  in  connection  with  any  proceeding,  actual  or
threatened,  to which they may be made a party by reason of their  service to or
at the  request  of the  corporation,  including  service in their  capacity  as
officers,  unless  it is  established  that:  (i)  the  act or  omission  of the
indemnified party was committed in bad faith; (ii) the indemnified party did not
believe such act or omission to be in, or not opposed to, the best  interests of
the corporation;  (iii) in the case of any criminal proceeding,  the indemnified
party had reasonable cause to believe that the act or omission was unlawful;  or
(iv) the indemnified party is adjudged to be liable to the corporation  unless a
court of  competent  jurisdiction  determines  that such  person is  entitled to
indemnity. The corporation shall advance to any director seeking indemnification
pursuant  to Section 7.1  expenses,  including  attorneys'  fees,  actually  and
reasonably  incurred  in  defending  any  civil  or  criminal  action,  suit  or
proceeding  in  advance  of any  final  disposition  of  such  action,  suit  or
proceeding  upon  receipt  of an  undertaking  by or on behalf  of the  director
seeking indemnification to repay such amount if it is ultimately determined that
he is not  entitled  to be  indemnified  by the  corporation.  In the  event the
corporation  is  requested  to  indemnify  an  existing  or former  director  in
connection with any threatened, pending or completed action or suit by or in the
right of the corporation to procure  judgment in its favor by reason of the fact
that  such  person  was a  director,  officer,  or  employee  or  agent  of  the
corporation,  or is or was  serving at the  request of the  corporation  in such
capacity,   the  corporation  shall  indemnify  such  person  against  expenses,
including  attorneys'  fees, but excluding  judgments and fines, and for amounts
paid in settlement,  actually and reasonably  incurred by him in connection with
the defense or  settlement  of such action or suit,  if such  person  acted,  or
failed to act, in good faith and in a manner he reasonably believed to be in, or
not  opposed  to,  the  best  interests  of  the  corporation,  except  that  no
indemnification  shall be made in respect  to any  claim,  issue or matter as to
which such  person  shall have been  adjudged  to be liable to the  corporation,
unless  and only to the  extent  that a court in which  such  action or suit was
brought shall  determine,  upon  application,  that despite the  adjudication of
liability,  but in view of all  circumstances of the case, such person is fairly

                                       -4-

and  reasonably  entitled to indemnity for such  expenses  which the court shall
deem to be proper.

     Whenever any existing or former director shall report to the President that
he has  incurred or may incur  expenses  described  in Section 7.1, the Board of
Directors  (other  than any  interested  director)  shall,  at its next  regular
meeting  or at a special  meeting  held  within a  reasonable  time  thereafter,
determine whether,  in regard to the matter involved,  the person in question is
entitled to  indemnification  pursuant to Section  7.1. If the Board  determines
that the standards of Section 7.1 are met, indemnification shall be made. In the
event the Board of Directors  refuses to indemnify a person who is determined by
a court of  competent  jurisdiction  to be  entitled  to  indemnification  under
Section 7.1 or applicable law, the  corporation  shall, in addition to extending
such  indemnification,  reimburse the person entitled to indemnification for all
attorneys' fees and costs of court actually incurred. The corporation shall have
the right to refuse  indemnification in any instance in which the person to whom
indemnification  would  otherwise  have been  extended  unreasonably  refuses to
cooperate  in the  investigation  or  defense  of such  matter or to permit  the
corporation, at its own expense, to retain counsel of its own choosing to defend
him.

     The  Board  of  Directors  may  authorize  the   corporation  to  indemnify
directors, officers, or employees to the fullest extent permitted by law.

     The indemnification  rights contained in Section 7 of the Company's Amended
and  Restated  Bylaws  shall not be exclusive of or preclude any other rights of
indemnification to which a director, officer, employee or agent may be entitled,
whether pursuant to law or agreement.

     The Company has entered into  indemnification  agreements  with each of its
directors that  requires,  among other things,  that the Company  indemnify each
director  to the  fullest  extent  not  prohibited  by  Arizona  law,  including
indemnity for a director's  service in his capacity as an officer,  and that the
Company  advances all related fees and expenses to the  directors  and officers,
subject  to an  agreement  to  reimburse  the  Company  if  it  is  subsequently
determined that indemnification is not permitted."

ITEM 7: EXEMPTION FROM REGISTRATION CLAIMED.

     Not applicable.

ITEM 8: EXHIBITS.

     The exhibits to the Registration  Statement are listed in the Exhibit Index
included elsewhere herein.

ITEM 9: UNDERTAKINGS.

     A.   The undersigned Registrant hereby undertakes:

                                       -5-

          1.   To file,  during  any  period in which  offers or sales are being
               made, a post-effective amendment to this Registration Statement:

               a.   To include any  prospectus  required by Section  10(a)(3) of
                    the Securities Act of 1933 (the "Securities Act");

               b.   To reflect  in the  prospectus  any facts or events  arising
                    after the effective date of the  Registration  Statement (or
                    the most recent  post-effective  amendment  thereof)  which,
                    individually  or in the  aggregate,  represent a fundamental
                    change  in the  information  set  forth in the  Registration
                    Statement;

               c.   To include any material information with respect to the plan
                    of distribution not previously disclosed in the Registration
                    Statement or any material change to such  information in the
                    Registration Statement.

          2.   That,  for the purpose of  determining  any  liability  under the
               Securities  Act,  each  such  post-effective  amendment  shall be
               deemed  to  be a  new  registration  statement  relating  to  the
               securities  offered therein,  and the offering of such securities
               at that time shall be deemed to be the initial bona fide offering
               thereof; provided that paragraphs A.1.a and A.1.b do not apply if
               the  registration  statement  is on Form  S-3 or Form S-8 and the
               information to be included in a post-effective amendment to those
               paragraphs  is  contained  in  periodic   reports  filed  by  the
               registrant  pursuant  to  Section  13 or  Section  15(d)  of  the
               Securities   Exchange  Act  of  1934  that  are  incorporated  by
               reference in this registration statement.

          3.   To  remove  from   registration  by  means  of  a  post-effective
               amendment any of the  securities  being  registered  which remain
               unsold at the termination of the offering.

     B.   The undersigned  registrant  hereby  undertakes  that, for purposes of
          determining  any  liability  under the  Securities  Act of 1933,  each
          filing of the registrant's  annual report pursuant to Section 13(a) or
          Section  15(d)  of  the  Securities  Exchange  Act  of  1934  that  is
          incorporated  by  reference  in the  registration  statement  shall be
          deemed to be a new registration  statement  relating to the securities
          offered  therein,  and the  offering of such  securities  at that time
          shall be deemed to be the initial bona fide offering thereof.

     C.   The undersigned registrant hereby undertakes to deliver or cause to be
          delivered with the  prospectus,  to each person to whom the prospectus
          is sent or given, the latest annual report to security holders that is
          incorporated by reference in the prospectus and furnished  pursuant to
          and  meeting  the  requirements  of Rule 14a-3 or Rule 14c-3 under the
          Securities   Exchange  Act  of  1934;  and,  where  interim  financial
          information  required to be presented by Article 3 of  Regulation  S-X
          are not set  forth  in the  prospectus,  to  deliver,  or  cause to be
          delivered to each person to whom the prospectus is sent or given,  the

                                       -6-

          latest quarterly report that is specifically incorporated by reference
          in the prospectus to provide such interim financial information.

     D.   Insofar  as   indemnification   for  liabilities   arising  under  the
          Securities  Act of 1933 may be  permitted to  directors,  officers and
          controlling  persons  of the  registrant  pursuant  to  the  foregoing
          provisions,  or otherwise, the registrant has been advised that in the
          opinion of the Securities and Exchange Commission such indemnification
          is against  public  policy as expressed in the Act and is,  therefore,
          unenforceable.  In the event that a claim for indemnification  against
          such liabilities (other than the payment by the registrant of expenses
          incurred or paid by a director,  officer or controlling  person of the
          registrant  in  the  successful   defense  of  any  action,   suit  or
          proceeding)  is  asserted  by such  director,  officer or  controlling
          person  in  connection  with  the  securities  being  registered,  the
          registrant  will,  unless in the opinion of its counsel the matter has
          been  settled  by  controlling   precedent,   submit  to  a  court  of
          appropriate  jurisdiction the question whether such indemnification by
          it is  against  public  policy  as  expressed  in the Act and  will be
          governed by the final adjudication of such issue.

                                       -7-

                                   SIGNATURES

     THE REGISTRANT. Pursuant to the requirements of the Securities Act of 1933,
the Registrant certifies that it has reasonable grounds to believe that it meets
all of the  requirements  for  filing  on  Form  S-8 and has  duly  caused  this
Registration Statement to be signed on its behalf by the undersigned,  thereunto
duly authorized,  in the City of Phoenix,  State of Arizona, on this 30th day of
May, 2003.

                                       KNIGHT TRANSPORTATION, INC.,
                                       an Arizona corporation


                                       By /s/ Kevin P. Knight
                                          --------------------------------------
                                          Kevin P. Knight, Chairman of the Board
                                          and Chief Executive Officer


     Pursuant  to  the   requirements  of  the  Securities  Act  of  1933,  this
Registration  Statement  has  been  signed  by  the  following  persons  in  the
capacities and on the date indicated.

                SIGNATURE AND TITLE                                     DATE
                -------------------                                     ----

/s/ Kevin P. Knight                                                 May 30, 2003
-----------------------------------------------------
Kevin P. Knight, Chairman of the Board,
Chief Executive Officer, Director

/s/ Gary J. Knight                                                  May 30, 2003
-----------------------------------------------------
Gary J. Knight, President, Director


/s/ Keith T. Knight                                                 May 30, 2003
-----------------------------------------------------
Keith T. Knight,
Executive Vice President, Director

/s/ Timothy M. Kohl                                                 May 30, 2003
-----------------------------------------------------
Timothy M. Kohl, Director, Chief Financial Officer


                                                                    May 30, 2003
-----------------------------------------------------
Donald A. Bliss, Director


/s/ Randy Knight                                                    May 30, 2003
-----------------------------------------------------
Randy Knight, Director


                                                                    May 30, 2003
-----------------------------------------------------
G.D. Madden, Director


                                                                    May 30, 2003
-----------------------------------------------------
Matt Salmon, Director


/s/ Mark Scudder                                                    May 30, 2003
-----------------------------------------------------
Mark Scudder, Director

                                       -8-

                                  EXHIBIT INDEX

                                                                    Sequentially
                                                                      Numbered
Exhibit No.                        Description                        Pages(1)
-----------                        -----------                        --------

4.1            Articles 4, 10 and 11 of the Restated Articles of
               Incorporation of the Company. (Incorporated by
               reference to Exhibit 4.1 to the Company's
               Registration Statement on form S-3 No. 333-72130)

4.2            Sections 2 and 5 of the Amended and Restated
               Bylaws of the Company. (Incorporated by reference
               to Exhibit 4.2 to the Company's Registration
               Statement on form S-3 No. 333-72130)

4.3            Knight Transportation, Inc. 2003 Stock Option
               Plan. (Incorporated by reference from Exhibit 1 to
               the Company's Proxy Statement filed April 4, 2003
               on Schedule 14A.)

5.1*           Opinion of Ryley Carlock & Applewhite, a
               professional association

23.1*          Consent of Ryley Carlock & Applewhite, a
               professional association (see Exhibit 5.1)

23.2*          Consent of KPMG LLP, independent public accountants


*    Filed herewith.

(1)  The  page  numbers  where  exhibits  (other  than  those   incorporated  by
     reference)  may  be  found  are  indicated  only  on  the  manually  signed
     Registration Statement.

                                       -9-