Exhibit 5

The Directors
Cordiant Communications Group plc
121-141 Westbourne Terrace
London
W2 6JR

                                                     Our Ref:     MHL/WD/555974
                                                     Direct Line: 020 7849 2539
                                                     E-mail: mhl@macfarlanes.com

4 February 2000



Dear Sirs

REGISTRATION STATEMENT ON FORM-4

As English solicitors for Cordiant Communications Group plc, a public limited
company incorporated under the laws of England and Wales ("the Company"), we
have been requested to render this opinion in connection with the proposed
registration under the United States Securities Act 1933, as amended ("the
Securities Act"), of Ordinary Shares of 50p each in the capital of the Company
("the Ordinary Shares") to be issued in connection with the Agreement and Plan
of Merger dated as of 9 November 1999 made by and among the Company, Healthworld
Acquisition Corp., a wholly-owned subsidiary of the Company ("Merger Sub") and
Healthworld Corporation ("Healthworld"), as amended by an Amendment Agreement
dated 2 February 2000 among the same parties ("the Merger Agreement"), providing
for the merger of Healthworld Acquisition Corp, a wholly-owned subsidiary of the
Company, with and into Healthworld.


               
1                 For the purpose of this opinion we have examined copies,
                  certified or otherwise authenticated to our satisfaction, of:-

1.1               the Certificate of Incorporation and each Certificate of
                  Incorporation on change of name of the Company;

1.2               the Memorandum of Association and Articles of Association of
                  the Company;

1.3               the Merger Agreement; and

1.4               such records of proceedings of the Board of Directors of the
                  Company, records of public officials and other documents as we
                  have deemed necessary or appropriate under the circumstances.






               
                  We have assumed the genuineness of all signatures, the
                  authenticity of all documents submitted to us as originals and
                  the conformity to the originals of all documents submitted to
                  us as copies.

2                 For the purpose of this opinion we have also assumed that:-

2.1               the Extraordinary General Meeting of the Company to be held in
                  connection with the Transaction ("the EGM") will be convened
                  by the posting of the Circular and Listing Particulars of the
                  Company in the form exhibited to the Registration Statement to
                  shareholders of the Company entitled to receive notice of
                  general meetings not less than twenty-one clear days prior to
                  the date fixed for the EGM and that Resolution 1 ("the
                  Resolution") set out in that notice will be duly passed at the
                  EGM and not subsequently amended or revoked prior to the
                  allotment and issuance of the Ordinary Shares;

2.2               prior to the allotment and issue of the Ordinary Shares there
                  shall have been delivered to the Company a report in
                  accordance with Sections 103 and 108 of the Companies Act 1985
                  ("the Report") and a copy of the Report shall have been
                  delivered to the Exchange Agent (as such term as defined in
                  the Merger Agreement), whether before or after the EGM; and

2.3               following the passing of the Resolution and delivery of the
                  Report as described above, a meeting of the Board of Directors
                  or a duly authorised and constituted Committee thereof will be
                  duly convened and held and will duly resolve to allot and
                  issue the Ordinary Shares and such resolution(s) will not
                  subsequently be amended or revoked prior to the allotment and
                  issuance of the Ordinary Shares.

3                 On the basis of and subject to the foregoing, we are of the
                  opinion that the Ordinary Shares will, when issued pursuant to
                  and in accordance with the Merger Agreement, be legally and
                  validly issued, fully paid and non-assessable (ie. no further
                  contribution in respect of the Ordinary Shares will be
                  required to be made to the Company by the holders thereof, by
                  reason only of their being such holders).


This opinion is limited to the law of England and Wales as currently in effect
and applied by the courts thereof and is given on the basis that this opinion
will be governed by and construed in accordance with such law.

We consent to the filing of this opinion as an exhibit to the Registration
Statement and to the use of our name in the Registration Statement and in the
Prospectus-Proxy Statement contained therein under the heading "Certain Legal
Matters". In giving such consent, we do not admit that we are in the category of
persons whose consent is required under Section 7 of the Securities Act.

Yours faithfully

/s/Macfarlanes