Rule 424(b)(2) File No. 333-33814 Pricing Supplement #81 dated July 29th, 2004 to the Prospectus Dated April 12, 2000 and Prospectus Supplement Dated October 21, 2003 Marshall & Ilsley Corporation MiNotes SM Due from 9 Months to 30 Years Trade Date: July 26, 2004 Issue Price: 100% Original Issue Date: July 29, 2004 Principal Amount: $412,000.00 Maturity Date: March 15, 2010 Interest Rate: 4.000% Interest Payment Dates: 08/15/04 & Monthly thereafter Purchasing Agent acting as Principal: Merrill Lynch & Co. Purchasing Agent Commission: 1.00% Proceeds Before expenses: 99.00% ($407,880.00) Survivor's Option: Yes Redemption or Repayment: At Maturity Redemption/Repayment Terms: Not Applicable Minimum Denomination: $1,000 minimum investment with increments of $1,000 CUSIP No.: 57183MDN7 Original Issue Discount: No Notes: All trades settle without accrued interest and clear SDFS: DTC Book-Entry only Merrill Lynch DTC Participant Number: 161