UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                               ------------------

                                    FORM 6-K

                        REPORT OF FOREIGN PRIVATE ISSUER
                        PURSUANT TO RULE 13a-16 OR 15d-16
                    UNDER THE SECURITIES EXCHANGE ACT OF 1934
                               ------------------
                          For the month of August 2004

                        Commission File Number: 001-31368

                                SANOFI-SYNTHELABO
                 (Translation of registrant's name into English)

                   174, avenue de France, 75013 Paris, FRANCE
                    (Address of principal executive offices)

     Indicate  by check mark  whether the  registrant  files or will file annual
reports under cover Form 20-F or Form 40-F.

                           Form 20-F [X]              Form 40-F [ ]

     Indicate  by check mark if the  registrant  is  submitting  the Form 6-K in
paper as permitted by Regulation S-T Rule 101(b)(1): ________

     Indicate  by check mark if the  registrant  is  submitting  the Form 6-K in
paper as permitted by Regulation S-T Rule 101(b)(7): ________

     Indicate by check mark whether the registrant by furnishing the information
contained  in this  Form is  also  thereby  furnishing  the  information  to the
Commission pursuant to Rule 12g3-2(b) under the Securities Exchange Act of 1934.

                           Yes [ ]                           No [X]

     If "Yes" marked,  indicate below the file number assigned to the registrant
in connection with Rule 12g3-2(b): 82-________


     This  Report on Form 6-K shall be deemed to be  incorporated  by  reference
into  Sanofi-Synthelabo's  Registration  Statement on Form F-4 (Registration No.
333-112314),  as post-effectively amended and declared effective on May 13, 2004
by the United States Securities Exchange Commission, and the related prospectus,
dated April 9, 2004, and the  prospectus  supplement,  dated May 27, 2004,  each
filed pursuant to Rule 424(b) under the United States Securities Act of 1933, as
amended,  and shall be part thereof from the date on which this Report is filed,
to the extent not  superseded  by  documents  or reports  subsequently  filed or
furnished.





     On August 13, 2004, at the request of the Autorite des marches  financiers,
the French stock market regulator,  Sanofi-Synthelabo  published an announcement
of the opening of the subsequent  offering  period in its offer for Aventis.  An
English  translation of the French  announcement  is attached  hereto as Exhibit
99.1.





                                   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, thereunto duly authorized.


Dated: August 13, 2004                       SANOFI-SYNTHELABO


                                             By:   /s/ Marie-Helene Laimay
                                                --------------------------------
                                                Name:  Marie-Helene Laimay
                                                Title: Senior Vice President and
                                                       Chief Financial Officer





                                  EXHIBIT INDEX


Exhibit No.                        Description
-----------                        -----------
Exhibit 99.1        English translation of text of advertisement required to be
                    published by Sanofi-Synthelabo in Les Echos on August 13,
                    2004, announcing the opening of the subsequent offering
                    period