COLUMBIA ACORN TRUST

227 W. MONROE STREET, SUITE 3000

CHICAGO, IL  60602

October 1, 2010

BY EDGAR

Securities and Exchange Commission

100 F Street, N.E.

Washington, D.C.  20549

Ladies and Gentlemen:

Columbia Acorn Trust

Columbia Acorn Fund

Columbia Acorn International

Columbia Acorn USA

Columbia Acorn Select

Columbia Acorn International Select

1933 Act Registration No. 002-34223

1940 Act Registration No. 811-01829

In accordance with Rule 497(j) of Regulation C under the Securities Act of 1933, Columbia Acorn Trust (the “Trust”) certifies that:

a. the forms of prospectuses and statement of additional information for the Class I shares of Columbia Acorn Fund, Columbia Acorn International, Columbia Acorn USA, Columbia Acorn Select and Columbia Acorn International Select, each a series of the Trust, that would have been filed under paragraph (c) of Rule 497 would not have differed from that contained in the most recent post-effective amendment to the Trust’s registration statement on Form N-1A; and

b. the text of the most recent post-effective amendment to the Trust’s registration statement was filed with the Commission via EDGAR on September 27, 2010.

Very truly yours,
COLUMBIA ACORN TRUST
By:	/s/ Bruce H. Lauer
	Bruce H. Lauer, Vice President, Secretary and Treasurer