UNITED STATES

                       SECURITIES AND EXCHANGE COMMISSION

                             WASHINGTON, D.C. 20549



                                    FORM 8-K

                                 CURRENT REPORT


     PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934


                Date of Report (Date of earliest event reported)

                                  May 30, 2003


                          BIOSOURCE INTERNATIONAL, INC.
             (Exact name of registrant as specified in its charter)

            Delaware                      0-21930                77-0340829
(State or other jurisdiction of       (Commission File         (IRS Employer
         incorporation)                    Number)           Identification No.)



        542 Flynn Road, Camarillo, California                      93012
       (Address of principal executive offices)                  (Zip Code)

       Registrant's telephone number, including area code: (805) 987-0086





ITEM 5. - OTHER EVENTS.

     Since the end of the  Company's  first  quarter  ended March 31, 2003,  the
Company has spent $2,793,000  repurchasing 548,100 shares of its common stock in
accordance with its previously  approved stock repurchase  program.  The largest
repurchase  occurred  on May  30,  2003,  where  the  Company  spent  $2,450,000
repurchasing  490,000 shares of its common stock.  The Company intends to retire
all common shares repurchased.


ITEM 7. - FINANCIAL STATEMENTS, PRO FORMA FINANCIAL INFORMATION AND EXHIBITS.

     (a)  Financial Statements. None.

     (b)  Pro Forma Financial Information. None.

     (c)  Exhibits. None.





                                   SIGNATURES

         Pursuant to the  requirements  of the Securities  Exchange Act of 1934,
the  Registrant  has duly  caused  this report to be signed on its behalf by the
undersigned hereunto duly authorized.

                                       BIOSOURCE INTERNATIONAL, INC.



June 3, 2003                           /s/ Charles C. Best
                                       -----------------------------
                                       Charles C. Best
                                       Chief Financial Officer