EXHIBIT 99.2 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 NB&T Financial Group, Inc. (the "Company"), on Form 10-K for the period ended December 31, 2002, dated the date of this Certification (the "Report"), I, Timothy L. Smith, the President and the Chief Executive 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: 1. The Report 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. Date: March 18, 2003 /s/ Timothy L. Smith ------------------------------------- Timothy L. Smith President and Chief Executive Officer 74