RPM International (RPM) 10-Q 2008 Q3 Quarterly report

Exhibit No. 32.1

CERTIFICATION

Pursuant to 18 U.S.C. Section 1350, the undersigned officer of RPM International Inc., a Delaware corporation (the “Company”), does hereby certify, to such officer’s knowledge, that the Company’s Quarterly Report onForm 10-Q for the quarter ended February 29, 2008 (the“Form 10-Q”) fully complies with the requirements of Section 13(a) or 15(d), as applicable, of the Securities Exchange Act of 1934 and that the information contained in theForm 10-Q fairly presents, in all material respects, the financial condition and results of operations of the Company as of, and for, the periods presented in theForm 10-Q.

/s/  Frank C. Sullivan

Frank C. Sullivan

President and Chief Executive Officer

Dated: April 8, 2008

The foregoing Certification is being furnished solely pursuant to 18 U.S.C. Section 1350 and is not being filed as part of theForm 10-Q or as a separate disclosure document.