Exhibit 32.2


                            CERTIFICATION PURSUANT TO
                             18 U.S.C. SECTION 1350,
                             AS ADOPTED PURSUANT TO
                  SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002


     In connection  with the Annual Report of Knight  Transportation,  Inc. (the
"Company")  on Form 10-K for the period ended  December 31, 2003,  as filed with
the Securities  and Exchange  Commission on the date hereof (the  "Report"),  I,
David A. Jackson, Chief Financial Officer of the Company,  certify,  pursuant to
18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley
Act of 2002, that to the best of my knowledge:

     (1)  The Report fully  complies with the  requirements  of Section 13(a) or
          15(d) of the Securities Exchange Act of 1934; and

     (2)  The  information  contained  in the  Report  fairly  presents,  in all
          material respects,  the financial  condition and results of operations
          of the Company.


                                             /s/ David A. Jackson
                                             -----------------------------------
                                             David A. Jackson
                                             Chief Financial Officer
                                             February 25, 2004

A signed  original of this  written  statement  required by Section 906 has been
provided  to  Knight  Transportation,  Inc.  and  will  be  retained  by  Knight
Transportation,  Inc. and furnished to the Securities and Exchange Commission or
its staff upon request.