Exhibit 32.1

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


         I, John M. Yeaman, certify, pursuant to 18 U.S.C. 1350, as adopted
pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that the Annual
Report on Form 10-K of Tyler Technologies, Inc. for the fiscal year ended
December 31, 2003 fully complies with the requirements of Section 13(a) or 15(d)
of the Securities Exchange Act of 1934 and that information contained in such
Annual Report on Form 10-K fairly presents, in all material respects, the
financial condition and results of operations of Tyler Technologies, Inc.


Dated: February 24, 2004            By: /s/ John M. Yeaman
                                        ----------------------------------------
                                        John M. Yeaman
                                        President and Chief Executive Officer