Liberty Acorn Trust

                       Supplement dated August 31, 2001
                      to Prospectus dated May 1, 2001 of
                         Liberty Acorn Fund - Class Z
                     Liberty Acorn International - Class Z
                          Liberty Acorn USA - Class Z
                        Liberty Acorn Twenty - Class Z
                     Liberty Acorn Foreign Forty - Class Z

Effective immediately, the section entitled "Portfolio Managers" on pages 33
through 35 of the Funds' Prospectus is revised as follows:

 .    The second paragraph under the heading on page 33 will be deleted.

 .    The sole paragraph on page 35 will be deleted and replaced with the
following:

Chris Olson
Liberty Acorn Foreign Forty, Co-portfolio manager

Mr. Olson has managed Liberty Acorn Foreign Forty since September, 2001.  He has
been a member of the international analytical team at Liberty WAM since January
2001.  Mr. Olson also is a co-portfolio manager of two international mutual
funds underlying variable insurance products.  Prior to joining Liberty WAM, Mr.
Olson was most recently a director and portfolio strategy analyst with UBS Asset
Management/Brinson Partners.  He is a CFA and earned a BA from Middlebury
College, a MBA from the University of Pennsylvania's Wharton School of Business
and a MA in International Studies from the University of Pennsylvania's School
of Arts and Sciences.

Todd Narter
Liberty Acorn Foreign Forty, Co-portfolio manager

Mr. Narter has managed Liberty Acorn Foreign Forty since September, 2001.  He
has been a member of the international analytical team at Liberty WAM since June
1997.  Mr. Narter also is a co-portfolio manager of two international mutual
funds underlying variable insurance products.  Prior to joining Liberty WAM, Mr.
Narter spent seven years working in Japan in the electronics industry, mainly as
a product manager for Teradyne.  He is a CFA and earned a BS from the University
of Texas and a MS from Stanford University.


                              Liberty Acorn Trust

                       Supplement dated August 31, 2001
                      to Prospectus dated May 1, 2001 of
                Liberty Acorn Foreign Forty - Class A, B and C

Effective immediately, (i) the heading in the Table of Contents entitled
"Portfolio Managers/The Investment Team" on the cover page of the Fund's
Prospectus is deleted and replaced with "Portfolio Managers" and (ii) the
section entitled "Portfolio Managers/The Investment Team" on page 18 of the
Funds' Prospectus is revised as follows:

Portfolio Managers
The co-portfolio managers are responsible for making daily investment decisions.

Chris Olson
Liberty Acorn Foreign Forty, Co-portfolio manager

Mr. Olson has managed Liberty Acorn Foreign Forty since September, 2001.  He has
been a member of the international analytical team at Liberty WAM since January
2001.  Mr. Olson also is a co-portfolio manager of two international mutual
funds underlying variable insurance products.  Prior to joining Liberty WAM, Mr.
Olson was most recently a director and portfolio strategy analyst with UBS Asset
Management/Brinson Partners.  He is a CFA and earned a BA from Middlebury
College, a MBA from the University of Pennsylvania's Wharton School of Business
and a MA in International Studies from the University of Pennsylvania's School
of Arts and Sciences.

Todd Narter
Liberty Acorn Foreign Forty, Co-portfolio manager

Mr. Narter has managed Liberty Acorn Foreign Forty since September, 2001.  He
has been a member of the international analytical team at Liberty WAM since June
1997.  Mr. Narter also is a co-portfolio manager of two international mutual
funds underlying variable insurance products.  Prior to joining Liberty WAM, Mr.
Narter spent seven years working in Japan in the electronics industry, mainly as
a product manager for Teradyne.  He is a CFA and earned a BS from the University
of Texas and a MS from Stanford University.


                              Liberty Acorn Trust

                       Supplement dated August 31, 2001
                      to Prospectus dated May 1, 2001 of
                     Liberty Acorn Foreign Forty - Class Z

Effective immediately, (i) the heading in the Table of Contents entitled
"Portfolio Managers/The Investment Team" on the cover page of the Fund's
Prospectus is deleted and replaced with "Portfolio Managers" and (ii) the
section entitled "Portfolio Managers/The Investment Team" on page 16 of the
Funds' Prospectus is revised as follows:

Portfolio Managers
The co-portfolio managers are responsible for making daily investment decisions.

Chris Olson
Liberty Acorn Foreign Forty, Co-portfolio manager

Mr. Olson has managed Liberty Acorn Foreign Forty since September, 2001.  He has
been a member of the international analytical team at Liberty WAM since January
2001.  Mr. Olson also is a co-portfolio manager of two international mutual
funds underlying variable insurance products.  Prior to joining Liberty WAM, Mr.
Olson was most recently a director and portfolio strategy analyst with UBS Asset
Management/Brinson Partners.  He is a CFA and earned a BA from Middlebury
College, a MBA from the University of Pennsylvania's Wharton School of Business
and a MA in International Studies from the University of Pennsylvania's School
of Arts and Sciences.

Todd Narter
Liberty Acorn Foreign Forty, Co-portfolio manager

Mr. Narter has managed Liberty Acorn Foreign Forty since September, 2001.  He
has been a member of the international analytical team at Liberty WAM since June
1997.  Mr. Narter also is a co-portfolio manager of two international mutual
funds underlying variable insurance products.  Prior to joining Liberty WAM, Mr.
Narter spent seven years working in Japan in the electronics industry, mainly as
a product manager for Teradyne.  He is a CFA and earned a BS from the University
of Texas and a MS from Stanford University.