<DOCUMENT>
<TYPE>EX-23.1
<SEQUENCE>2
<FILENAME>k06051exv23w1.txt
<DESCRIPTION>CONSENT OF INDEPENDENT PUBLIC ACCOUNTANTS
<TEXT>
<PAGE>

                                  EXHIBIT 23.1

            CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We hereby consent to the incorporation by reference in the Registration
Statement No. 333-117763 on Form S-8 of Mercantile Bank Corporation of our
report dated May 18, 2006, which is included in this Annual Report on Form 11-K
of Mercantile Bank of Michigan 401(k) Plan for the year ended December 31, 2005.

                                        /s/ Crowe Chizek and Company LLC
                                        --------------------------------------
                                        Crowe Chizek and Company LLC

South Bend, Indiana
June 19, 2006
</TEXT>
</DOCUMENT>