Dewey Ballantine LLP
                           1301 Avenue of the Americas
                            New York, New York 10019





                                                               June 25, 1999








Consolidated Edison Company of
  New York, Inc.
4 Irving Place
New York, New York 10003

            Re:  Registration Statement on Form S-3

Dear Sirs:

            We have acted as special tax counsel to Consolidated  Edison Company
of New York,  Inc.  (the  "Company")  in  connection  with the  issuance of $275
million  aggregate  principal  amount of the Company's 7.35% Public Income Notes
(7.35%  Debentures,  Series 1999 A) due 2039 ("PINES").  We have participated in
the  preparation  of the  Registration  Statement  on Form S-3  relating  to the
Company's  debt  securities  (No.  333-45745),  which was declared  effective on
February 11, 1998, and the Prospectus  Supplement,  dated today, relating to the
PINES. The PINES will be issued pursuant to the Indenture,  dated as of December
1, 1990,  between the  Company  and the Chase  Manhattan  Bank,  as Trustee,  as
amended and supplemented by the First Supplemental Indenture,  dated as of March
6, 1996, in the form filed as an exhibit to the Registration Statement.

            On the basis and subject to the accuracy of the statements contained
in the materials  referred to above, and our consideration of such other matters
as we have  deemed  necessary,  it is our  opinion  that under  current  law the
material  federal  income  tax  consequences  to  holders  of  PINES  will be as
described under the heading  "Material  Federal Income Tax  Consequences" in the
Prospectus Supplement constituting part of the Registration Statement.  You have
not  requested,  and we do not  express,  an  opinion  concerning  any other tax
consequences  of the  issuance  of the  PINES.  This  opinion is not to be used,
circulated,  quoted or otherwise referred to for any purpose without our express
written permission.

            We hereby  consent to the filing of this opinion with the Securities
and Exchange  Commission as an exhibit to the Registration  Statement and to the
references to our firm in the section  captioned  "Material  Federal  Income Tax
Consequences" in the Prospectus Supplement constituting part of the Registration
Statement. In giving the foregoing consent, we do not thereby admit that we come
within the category of persons whose consent is required  under Section 7 of the
Securities  Act of 1933 or the  rules  and  regulations  of the  Securities  and
Exchange Commission thereunder.


                                    Very truly yours,



                                    /s/ Dewey Ballantine LLP