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

                                    FORM 6-K

                        REPORT OF FOREIGN PRIVATE ISSUER
                      PURSUANT TO RULE 13a-16 OR 15d-16 OF
                       THE SECURITIES EXCHANGE ACT OF 1934

                         For the month of October, 2005

                                   Serono S.A.
                    ---------------------------------------
                               (Registrant's Name)

                            15 bis, Chemin des Mines
                                 Case Postale 54
                                CH-1211 Geneva 20
                                   Switzerland
                          -----------------------------
                    (Address of Principal Executive Offices)

                                     1-15096
                    ---------------------------------------
                              (Commission File No.)

     (Indicate by check mark whether the registrant files or will file annual
reports under cover of 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" is marked, indicate below the file number assigned to the
registrant in connection with Rule 12g3-2(b): 82-       )
                                                 ------



                                                                          SERONO
                                                                biotech & beyond


Media Release


FOR IMMEDIATE RELEASE

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         SERONO ANNOUNCES FINAL SETTLEMENT OF SEROSTIM(R) INVESTIGATION

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GENEVA,  SWITZERLAND  --  OCTOBER 17, 2005  - Serono (virt-x: SEO and NYSE: SRA)
announced  today  that  its U.S. affiliates have agreed to settle the government
investigation led by the U.S. Attorney's office in Massachusetts into commercial
practices  related  to  Serostim(R).  This  investigation was part of an ongoing
industry-wide  investigation  by  the  states  and  the  federal  government  of
commercial  practices.  The  comprehensive  settlements  with  federal and state
agencies  will conclude all liabilities to the government in connection with the
investigation.

In  April 2005, the company announced that it had taken a $725 million provision
to  cover the settlement and related costs. The provision, which was recorded as
an  exceptional charge in the company's earnings report for the first quarter of
2005,  will  be  sufficient  to  cover the comprehensive settlements and related
costs.  The  comprehensive  settlements  also  include  a  Corporate  Integrity
Agreement, administered through the Office of the Inspector General.

"This  settlement concludes a four-year government investigation into commercial
practices  related to Serostim, and we are pleased to put the matter behind us,"
said  Thomas  G.  Gunning, Vice President and General Counsel, Serono U.S.  "The
activities  described  in  the  settlement were confined to one unit in our U.S.
operations  and  cover  a  brief period in our history.  Serono takes compliance
issues  very  seriously and has a rigorous compliance program to ensure that its
employees meet the highest ethical standards.  We now look forward to continuing
to focus and devote our energies on our core mission of developing treatments to
meet  unmet  medical  needs."

                                       ###

ABOUT  SERONO
Serono  is  a  global biotechnology leader.  The Company has eight biotechnology
products,  Rebif(R),  Gonal-f(R),  Luveris(R),  Ovidrel(R)/Ovitrelle(R),
Serostim(R),  Saizen(R),  Zorbtive(TM) and Raptiva(R).  In addition to being the
world  leader  in  reproductive  health,  Serono  has strong market positions in
neurology,  metabolism  and  growth and has recently entered the psoriasis area.
The  Company's  research programs are focused on growing these businesses and on
establishing  new  therapeutic  areas, including oncology.  Currently, there are
approximately  30  ongoing  development  projects.

In  2004,  Serono  achieved  worldwide revenues of US$2,458.1 million, and a net
income  of  US$494.2 million, making it the third largest biotech company in the
world.  Its  products  are  sold  in over 90 countries.  Bearer shares of Serono
S.A.,  the  holding



company,  are  traded on the virt-x (SEO) and its American Depositary Shares are
traded  on  the  New  York  Stock  Exchange  (SRA).


FORWARD-LOOKING  STATEMENT
Some  of  the  statements  in  this  press  release  are  forward  looking. Such
statements  are inherently subject to known and unknown risks, uncertainties and
other  factors  that  may  cause  actual results, performance or achievements of
Serono  S.A.  and  affiliates  to be materially different from those expected or
anticipated  in  the  forward-looking statements. Forward-looking statements are
based on Serono's current expectations and assumptions, which may be affected by
a  number  of  factors, including those discussed in this press release and more
fully  described  in  Serono's  Annual  Report  on Form 20-F filed with the U.S.
Securities  and Exchange Commission on March 16, 2005. These factors include any
failure  or  delay  in  Serono's ability to develop new products, any failure to
receive  anticipated  regulatory  approvals,  any  problems  in  commercializing
current  products  as  a  result of competition or other factors, our ability to
obtain  reimbursement  coverage  for  our  products,  the  outcome of government
investigations and litigation and government regulations limiting our ability to
sell  our  products.  Serono has no responsibility to update the forward-looking
statements  contained  in  this press release to reflect events or circumstances
occurring  after  the  date  of  this  press  release.

FOR MORE INFORMATION, PLEASE CONTACT:

MEDIA RELATIONS, USA:       INVESTOR RELATIONS, USA
Tel:   +1 781 681 2340      Tel:       +1 781 681 2552
Fax:   +1 781 6812935       Fax:       +1 781 681 2912
www.seronousa.com
-----------------

CORPORATE MEDIA RELATIONS:  CORPORATE INVESTOR RELATIONS:
Tel:  +41 22 739 36 00      Tel:      +41 22 739 36 01
Fax:  +41 22 739 30 85      Fax:      +41 22 739 30 22
www.serono.com              Reuters: SEO.VX / SRA.N
--------------              Bloomberg: SEO VX / SRA US



                                   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.



                                            SERONO S.A.
                                            a Swiss corporation
                                            (Registrant)



October 19, 2005                             By:    /s/ Stuart Grant
                                                    --------------------------
                                             Name:  Stuart Grant
                                             Title: Chief Financial Officer