Exhibit 23.1 CONSENT OF INDEPENDENT AUDITORS We consent to the incorporation by reference in the following documents of our report dated January 20, 1999 with respect to the consolidated financial statements of First Midwest Bancorp, Inc. included in the Annual Report (Form 10-K) for the year ended December 31, 1998: . Registration Statement (Form S-3 No. 33-20439) pertaining to the First Midwest Bancorp, Inc. Dividend Reinvestment and Stock Purchase Plan. . Registration Statement (Form S-8 No. 33-25136) pertaining to the First Midwest Bancorp Savings and Profit Sharing Plan. . Registration Statement (Form S-8 No. 33-42980) pertaining to the First Midwest Bancorp, Inc. 1989 Omnibus Stock and Incentive Plan. . Registration Statement (Form S-8 No. 333-42273) pertaining to the First Midwest Bancorp, Inc. 1989 Omnibus Stock and Incentive Plan. . Registration Statement (Form S-8 No. 333-63095) pertaining to the First Midwest Bancorp, Inc. Non-employee Director Stock Option Plan. . Registration Statement (Form S-8 No. 333-63097) pertaining to the First Midwest Bancorp, Inc. Nonqualified Retirement Plan. ERNST & YOUNG LLP Chicago, Illinois February 26, 1999 Exhibit 23.2 CONSENT OF INDEPENDENT AUDITORS We consent to the incorporation by reference in the following Registration Statements of our report dated January 19, 1998 with respect to the consolidated financial statements of Heritage Financial Services, Inc. included in this Annual Report on Form 10-K of First Midwest Bancorp, Inc. for the year ended December 31, 1998: . Registration Statement (Form S-3 No. 33-20439) pertaining to the First Midwest Bancorp, Inc. Dividend Reinvestment and Stock Purchase Plan. . Registration Statement (Form S-8 No. 33-25136) pertaining to the First Midwest Bancorp Inc. Savings and Profit Sharing Plan. . Registration Statement (Form S-8 No. 33-42980) pertaining to the First Midwest Bancorp, Inc. 1989 Omnibus Stock and Incentive Plan. . Registration Statement (Form S-8 No. 333-42273) pertaining to the First Midwest Bancorp, Inc. 1989 Omnibus Stock and Incentive Plan. . Registration Statement (Form S-8 No. 333-63095) pertaining to the First Midwest Bancorp, Inc. Non-employee Stock Option Plan. . Registration Statement (Form S-8 No. 333-63097) pertaining to the First Midwest Bancorp, Inc. Nonqualified Retirement Plan. ARTHUR ANDERSEN LLP Chicago, Illinois February 26, 1999