EXHIBIT 32.1

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

As of the date  hereof,  I, Steven G.  Mihaylo,  certify,  pursuant to 18 U.S.C.
Section 1350, as adopted  pursuant to Section 906 of the  Sarbanes-Oxley  Act of
2002, that the Quarterly Report of Inter-Tel,  Incorporated on Form 10-Q for the
fiscal  quarter  ended June 30, 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 Quarterly  Report on Form 10-Q fairly presents in
all material  respects the  financial  condition  and results of  operations  of
Inter-Tel, Incorporated.

                                     By:  /s/  Steven G. Mihaylo
                                         ---------------------------------------

                                   Name:  Steven G. Mihaylo
                                         ---------------------------------------

                                  Title:  Chief Executive Officer
                                         ---------------------------------------

                                  Dated:  August 14, 2003
                                         ---------------------------------------

                                       37