Simmons First National (SFNC) 10-Q 2003 Q3 Quarterly report

Exhibit 99.1

CERTIFICATION PURSUANT TO18
U.S.C. SECTION 1350, AS ADOPTED
PURSUANT TO SECTION 906 OF
THE SARBANES-OXLEY ACT OF 2002

        In connection with the Quarterly Report of Simmons First National Corporation (the “Company”), on Form 10-Q for the period ending September 30, 2003 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), and pursuant to 18 U.S.C. Section 1350, as adopted pursuant to ss. 906 of the Sarbanes-Oxley Act of 2002, J. Thomas May, Chairman, President and Chief Executive Officer of the Company, hereby certifies that:

    (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/ J. Thomas May
J. Thomas May
Chairman, President and
Chief Executive Officer
October 30, 2003