News Release

Mercantile Bancorp, Inc. Files With The SEC and American Stock Exchange

Quincy, IL - May 12, 2004 - Today Mercantile Bancorp, Inc. (OTCBB: MBCI) filed a registration statement with the United States Securities and Exchange Commission seeking to register the company's common stock under the federal Securities Exchange Act of 1934, according to Dan S. Dugan, its Chairman, President and CEO. The company anticipates the registration process to be complete some time this summer.

Concurrently with filing for registration, the company applied to list its common stock for trade on the American Stock Exchange. Presently, the common stock is quoted on the OTC Bulletin Board under the symbol "MBCI". Trading on the Amex would commence only upon the effectiveness of SEC registration and approval of the listing application. The commencement date and a new trading symbol will be publicly released upon approval and determination.

"We look forward to completing the registration and listing process and becoming a registered, Amex-listed company. We anticipate that the greater availability of information concerning the company and enhanced marketability of a stock listed with a national exchange will benefit our shareholders and the public generally."

No additional shares of the company's common stock are being issued in connection with this registration and listing.

Mercantile Bancorp, Inc. is a multi-state bank holding company headquartered in Quincy, Illinois. At December 31, 2003, the company managed total assets in excess of $906 million and total deposits over $758 million. Through its majority-owned subsidiaries, now consisting of 6 banks in Illinois, 2 banks in Missouri and 1 bank in Kansas, the company conducts full-service commercial and consumer banking business, engages in mortgage banking, trusts services, and asset management, and provides other financial services and products. In addition, the company has minority investments in 4 community banks in Missouri, Georgia and Florida.

This release contains information and "forward-looking statements" that relate to matters that are not historical facts and which are usually preceded by the words "may," "will," "should," "could," "would," "plan," "potential," "estimate," "project," "believe," "intend," "anticipate," "except," "target" and similar expressions. These forward-looking statements are subject to significant risks, assumptions and uncertainties, including, but not limited to, the acceptance of the registration statement by the Securities and Exchange Commission and the approval of the listing application by the American Stock Exchange. Because of these and other uncertainties, our actual results may be materially different from those described in these forward-looking statements. The forward-looking statements in this release speak only as of the date of the release, and we do not assume any obligation to update the forward-looking statements or to update the reasons why actual results could differ from those contained in the forward-looking statements.

Questions regarding this information should be directed to Mr. Dugan at (217) 223-7300, or by e-mail at investor.relations@mercbanx.com