Exhibit 31.2

                                  CERTIFICATION

I, Timothy M. Kohl, certify that:

     1.   I  have  reviewed  this  quarterly  report  on  Form  10-Q  of  Knight
          Transportation, Inc.;

     2.   Based on my  knowledge,  this  report  does  not  contain  any  untrue
          statement  of a  material  fact  or  omit to  state  a  material  fact
          necessary to make the statements  made, in light of the  circumstances
          under which such  statements were made, not misleading with respect to
          the period covered by this report;

     3.   Based on my knowledge,  the financial statements,  and other financial
          information  included in this report,  fairly  present in all material
          respects the financial condition, results of operations and cash flows
          of the  registrant  as of,  and for,  the  periods  presented  in this
          report;

     4.   The registrant's other certifying officer(s) and I are responsible for
          establishing  and maintaining  disclosure  controls and procedures (as
          defined  in  Exchange  Act  Rules  13a-15(e)  and  15d-15(e))  for the
          registrant and have:

              (a) Designed such disclosure  controls and  procedures,  or caused
              such  disclosure  controls and procedures to be designed under our
              supervision,  to ensure that material  information relating to the
              registrant, including its consolidated subsidiaries, is made known
              to us by others  within those  entities,  particularly  during the
              period in which this report is being prepared;

              (b) Evaluated the  effectiveness  of the  registrant's  disclosure
              controls  and   procedures   and  presented  in  this  report  our
              conclusions about the effectiveness of the disclosure controls and
              procedures,  as of the end of the period  covered  by this  report
              based on such evaluation; and

              (c)  Disclosed  in this  report  any  change  in the  registrant's
              internal control over financial reporting that occurred during the
              registrant's most recent fiscal quarter (the  registrant's  fourth
              fiscal  quarter  in  the  case  of  an  annual  report)  that  has
              materially affected, or is reasonably likely to materially affect,
              the registrant's internal control over financial reporting; and

     5.   The  registrant's  other  certifying  officer(s) and I have disclosed,
          based on our most recent evaluation of internal control over financial
          reporting, to the registrant's auditors and the audit committee of the
          registrant's  board of directors (or persons performing the equivalent
          functions):

              (a) All significant  deficiencies  and material  weaknesses in the
              design or operation of internal  control over financial  reporting
              which are reasonably  likely to adversely  affect the registrant's
              ability  to  record,  process,   summarize  and  report  financial
              information; and

              (b) Any fraud,  whether or not material,  that involves management
              or other employees who have a significant role in the registrant's
              internal control over financial reporting.

Date:    October 31, 2003
                                       /s/ Timothy M. Kohl
                                     -----------------------------------
                                     Timothy M. Kohl
                                     Chief Financial Officer