Rule 424(b)(2) File No. 333-33814 Pricing Supplement #80 dated July 22nd, 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 19, 2004 Issue Price: 100% Original Issue Date: July 22, 2004 Principal Amount: $415,000.00 Maturity Date: January 15, 2010 Interest Rate: 4.100% 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% ($410,850.00) 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.: 57183MDM9 Original Issue Discount: No Notes: All trades settle without accrued interest and clear SDFS: DTC Book-Entry only Merrill Lynch DTC Participant Number: 161