HALE AND DORR LLP
                               Counsellors at Law
                                 60 State Street
                           Boston, Massachusetts 02109
                        617-526-6000 . fax 617-526-5000

                                  June 17, 1998


International Telecommunication
 Data Systems, Inc.
225 High Ridge Road
Stamford, CT 06905

     Re: 1998 Stock Incentive Plan
         -------------------------

Ladies and Gentlemen:

     We have assisted in the preparation of a Registration Statement on Form S-8
(the "Registration Statement") to be filed with the Securities and Exchange
Commission relating to 1,125,000 shares (the "Shares") of Common Stock, $.01 par
value per share, of International Telecommunication Data Systems, Inc., a
Delaware corporation (the "Company"), issuable under the Company's 1998 Stock
Incentive Plan (the "Plan").

     We have examined the Certificate of Incorporation of the Company, the
By-laws of the Company, and originals, or copies certified to our satisfaction,
of all pertinent records of the meetings of the directors and stockholders of
the Company, the Registration Statement and such other documents relating to the
Company as we have deemed material for the purposes of this opinion.

     In examination of the foregoing documents, we have assumed the genuineness
of all signatures and the authenticity of all documents submitted to us as
originals, the conformity to original documents of all documents submitted to us
as certified, photostatic or facsimile copies, and the authenticity of the
originals of any such documents.

     Based on the foregoing, we are of the opinion that the Shares have been
duly authorized for issuance under the Plan, and the Shares, when issued and
paid for in accordance with the terms of the Plan and at a price per share in
excess of the par value per share for such Shares, will be legally issued, fully
paid and nonassessable.

     We hereby consent to the filing of this opinion with the Securities and
Exchange Commission in connection with the Registration Statement.

                                       Very truly yours,

                                       /s/ HALE AND DORR LLP