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 July, 2004

                                  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

Media Release

FOR IMMEDIATE RELEASE
---------------------


PRELIMINARY DATA SHOWED SUSTAINED CLINICAL BENEFIT FOR MODERATE-TO-SEVERE PLAQUE
PSORIASIS PATIENTS TREATED WITH RAPTIVA FOR 30 MONTHS

GENEVA,  Switzerland  - July 29, 2004 - Serono (virt-x: SEO and NYSE: SRA) today
announced  preliminary  30-month  (120  weeks)  results from an open-label study
evaluating  the  safety  and  efficacy  of  long-term  continuous treatment with
Raptiva(R)  (efalizumab)  in  adults  with  moderate-to-severe  chronic  plaque
psoriasis.  The study results were presented as a poster at the American Academy
of  Dermatology  ACADEMY  2004  meeting  in  New York. The results of this study
suggest  that  continuous,  weekly dosing of Raptiva provided sustained clinical
benefit  over  two-and-a-half  years.

Of  the  159  subjects  participating  in  the  study who completed 30 months of
treatment,  a  75%  or  greater improvement on the Psoriasis Area Severity Index
(PASI 75) was observed in 78% (124/159) of patients with weekly Raptiva therapy.
Ninety-one  percent  (145/159) of patients achieved a PASI 50 response, and 45 %
of  patients  (71/159)  achieved  a  90 % or greater PASI improvement (PASI 90).

"Given  that  psoriasis  is  a chronic condition, dermatologists are looking for
treatment  options  that  can  provide these patients with continuous control of
their  disease  over  the  long-term,"  said  Dr.  Craig  Leonardi, MD Associate
Clinical  Professor of Dermatology, St Louis University Medical School, USA, and
a  study  investigator.  "These data represent the first 30-month data available
for  any  advanced therapy for plaque psoriasis and support the continued use of
Raptiva  as  an  important  treatment  option  for  patients afflicted with this
chronic  disease."

STUDY DESIGN
In  this study, 339 patients received Raptiva weekly for an initial 12 weeks and
patients  with  a  PASI  50  response  or a static Physician's Global Assessment
response  of  'mild'  or  better  after  12  weeks of treatment were eligible to
continue on a once-weekly maintenance dose of 1mg/kg Raptiva for 12 week periods
starting  at  week  13. Of the 339 subjects who started the study, 290 qualified
for  continued treatment beyond 12 weeks. For each successive three-month period
of  treatment,  dropouts  during  that  period  were  analyzed  using their last
available  PASI  assessment,  but  were  excluded  from  the subsequent cohorts.

"These 30-month data give dermatologists additional insight into how Raptiva may
be  used  to  develop  long-term treatment strategies for the psoriasis patients
where  we  have  approval  in  Switzerland and Argentina and positive opinion in
Europe and Australia," said Dr. Franck Latrille, Senior Executive Vice President
Global  Product  Development  of  Serono.


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Adverse  events in this study were similar to what has been observed in previous
clinical  trials of Raptiva, and include headache, non-specific infection (e.g.,
common  colds),  chills,  pain,  nausea,  asthenia (weakness), and fever, all of
which  diminished  after  the first 1-2 doses. Further, there was no evidence of
accumulation  or  cumulative  toxicity.  At 30-months, the occurrence of serious
adverse  events  was  infrequent  which  is  consistent  with data from previous
Raptiva  Phase  III  studies.

                                       ***


ABOUT RAPTIVA(R)
Raptiva(R)  is  a  humanized  therapeutic  antibody  designed to selectively and
reversibly  block  the  activation, reactivation and trafficking of T-cells that
lead  to  the  development  of  psoriasis  symptoms.  Raptiva  is designed to be
administered once weekly via subcutaneous injection and can be self-administered
by  patients  at  home.
Serono  has  the  rights  to develop and market Raptiva worldwide outside of the
United  States  and  Japan.  On  March  16,  2004, Serono announced approval for
Raptiva  in  Switzerland  for  adult  patients  with  moderate-to-severe  plaque
psoriasis and on June 24, 2004 that it had received a unanimous positive opinion
from  the  Committee  of  Medicinal  Products  for Human Use (CHMP) recommending
approval  in  the  European  Commission region.  The company has also received a
positive  opinion for Raptiva in Australia and launched the product in Argentina
following  approval  there.
Development and marketing rights in the United States remain with Genentech Inc.
(NYSE:DNA)  and  its  U.S.  partner  XOMA  (Nasdaq:  XOMA).
More  than  3,500  patients in the U.S. and Europe have been included in Raptiva
trials  to  date, creating the largest existing database of patients taking part
in  studies  with  a  biological  therapy  for  psoriasis.

ABOUT PSORIASIS
Psoriasis  is  a  T-cell  mediated  disease  which  occurs  when skin cells grow
abnormally,  resulting in thick, red, scaly, inflamed patches. Plaque psoriasis,
the most common form of the disease is characterized by inflamed patches of skin
("lesions")  topped with silvery white scales. Psoriasis can be limited to a few
spots  or  involve  extensive  areas of the body, appearing most commonly on the
scalp,  knees, elbows and trunk. Although it is highly visible, psoriasis is not
a  contagious  disease.  While  there  are a number of medications that may help
control  the  symptoms  of  psoriasis,  there  currently  is  no  known  cure.


BACKGROUND MATERIAL
For  free  B-roll,  video and other content about Raptiva, psoriasis and Serono,
please  visit  the  Serono  Media  Center  www.thenewsmarket.com/Serono. You can
                                           ----------------------------
download  print-quality images and receive broadcast-standard video digitally or
by  tape  from  this  site.  Registration  and  video  is  free  to  the  media.


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) (Luveris(R) is not approved
in  the  USA).  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.
Currently,  there  are  approximately  30  ongoing  development  projects.

In  2003,  Serono  achieved  worldwide revenues of US$2,018.6 million, and a net
income  of  US$390.0 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).

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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 25, 2004. 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,  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:
  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
                                INVESTOR RELATIONS, USA
                                Tel:  +1 781 681 2552
                                Fax:  +1 781 681 2912


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                                   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)



July 29, 2004                           By:   /s/  Francois Naef
                                              ----------------------
                                              Name:  Francois Naef
                                              Title:  Secretary