Exhibit 99.3
OMB Number: 3235-0569          
Expires: January 31, 2003          

Statement Under Oath of Principal Executive Officer Regarding Facts and Circumstances Relating to Exchange Act Filings

I, Dennis J. Kuester, state and attest that:

(1)	To the best of my knowledge, based upon a review of the covered reports of Marshall & Ilsley Corporation, and, except as corrected or supplemented in a subsequent covered report:
	no covered report contained an untrue statement of a material fact as of the end of the period covered by such report (or in the case of a report on Form 8-K or definitive proxy materials, as of the date on which it was filed); and
	no covered report omitted to state a material fact necessary to make the statements in the covered report, in light of the circumstances under which they were made, not misleading as of the end of the period covered by such report (or in the case of a report on Form 8-K or definitive proxy materials, as of the date on which it was filed).
(2)	I have reviewed the contents of this statement with the Company's audit committee.
(3)	In this statement under oath, each of the following, if filed on or before the date of this statement, is a "covered report."
	Annual Report on Form 10-K for the fiscal year ended December 31, 2001 of Marshall & Ilsley Corporation;
	all reports on Form 10-Q, all reports on Form 8-K and all definitive proxy materials of Marshall & Ilsley Corporation filed with the Commission subsequent to the filing of the Form 10-K identified above; and
	any amendments to any of the foregoing.

/s/ Dennis J. Kuester                         Dennis J. Kuester August 13, 2002	Subscribed and sworn to before me this 13th day of August 2002.
	/s/ Randall J. Erickson                 Notary Public
	My Commission Expires:               Is permanent