EXHIBIT 23(a)

             CONSENT OF INDEPENDENT REGISTERED PUBIC ACCOUNTING FIRM




         We consent to the incorporation by reference in this Registration
Statement on Form S-8 of our report dated January 22, 2004 which appears in
Mercantile Bank Corporation's Annual Report on Form 10-K for the year ended
December 31, 2003.

                                            /s/ Crowe Chizek and Company LLC



Grand Rapids, Michigan
October 14, 2004