PROSPECTUS SUPPLEMENT
(TO PROSPECTUS DATED SEPTEMBER 5, 2000)


                 Charles River Laboratories International, Inc.
                                  Common Stock
                       Warrants to Purchase Common Stock

- -------------------------------------------------------------------------------

     We initially issued the warrants in a transaction exempt from the
registration requirements of the Securities Act of 1933. Each warrant entitles
the holder to purchase 7.60 shares of our common stock at an exercise price of
$5.19 per share, subject to adjustment in some circumstances. We filed a
registration statement (Registration No. 333-92383) in order to permit the
holders of these warrants and shares of our common stock acquired on exercise
of these warrants to resell those securities in transactions that are
registered under the Securities Act of 1933.

     On pages 52 through 55 of the prospectus contained in that registration
statement, there is a table that provides certain information with respect to
those holders. We have prepared this prospectus supplement to

     o add the following persons to the table as holders of warrants and
underlying shares of common stock:


                                           Number of Warrants and Underlying                     Ownership
                                              Common Stock Owned Prior to                       After Resale
                                                  Resale of Warrants                             of Warrants
                                         ---------------------------------------                -------------
                                                                   Percentage of
                                                      Number of       Common       Number of    Percentage of
                                                       Shares       Stock Owned     Warrants      Shares of
                                         Number of   Underlying      Prior to      Offered by       Common
Name and Address of Holders              Warrants   the Warrants      Resale         Holder         Stock
- ---------------------------------------  ---------  ------------   -------------   ----------   -------------
                                                                                       
Carlyle High Yield Partners, L.P.
520 Madison Avenue, 41st Floor
New York, NY 10022.....................   10,000        76,000           --          10,000           --

Carlyle High Yield Partners II, Ltd.
520 Madison Avenue, 41st Floor
New York, NY 10022.....................    3,000        22,800           --           3,000           --

TCW Crescent/Mach I, L.P.
865 South Figueroa Street, 21st Floor
Los Angeles, CA 90017..................    2,100        15,960           --           2,100           --



     None of the above holders has a material relationship with us, except as
described in the accompanying prospectus.


o replace the information contained in the table with respect to the following holders: Number of Warrants and Underlying Ownership Common Stock Owned Prior to After Resale Resale of Warrants of Warrants --------------------------------------- ------------- Percentage of Number of Common Number of Percentage of Shares Stock Owned Warrants Shares of Number of Underlying Prior to Offered by Common Name and Address of Holders Warrants the Warrants Resale Holder Stock - --------------------------------------- --------- ------------ ------------- ---------- ------------- TCW Leveraged Income Investment Trust L.P. 865 South Figueroa Street, 21st Floor Los Angeles, CA 90017................... 3,150 23,940 -- 3,150 -- TCW Leveraged Income Trust II L.P. 865 South Figueroa Street, 21st Floor Los Angeles, CA 90017................... 3,150 23,940 -- 3,150 -- TCW Crescent Mezzanine Partners II, L.P. 865 South Figueroa Street, 21st Floor Los Angeles, CA 90017................... 27,044 205,534 -- 27,044 -- TCW Crescent Mezzanine Trust II 865 South Figueroa Street, 21st Floor Los Angeles, CA 90017................... 6,556 49,826 -- 6,556 -- The date of this Prospectus Supplement is January 3, 2001. 2