Commerce Bancshares (CBSH) S-4 Registration of securities issued in business combination transactions

EXHIBIT 23(a)

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

The Board of Directors
Commerce Bancshares, Inc.:

     We consent to the use of our reports, dated February 27, 2006, with respect to the consolidated balance sheets of Commerce Bancshares, Inc. as of December 31, 2005 and 2004 and the related consolidated statements of income, stockholders’ equity, and cash flows for each of the years in the three-year period ended December 31, 2005, management’s assessment of the effectiveness of internal control over financial reporting as of December 31, 2005, and the effectiveness of internal control over financial reporting as of December 31, 2005, incorporated herein by reference, and to the reference to our firm under the heading “Experts” in the prospectus.

	/s/	KPMG LLP
Kansas City, Missouri May 26, 2006