Exhibit 5.1


                               November 17, 2003

EMC Corporation
176 South Street
Hopkinton, MA  01748

Ladies and Gentlemen:


         I am Senior Vice President and General Counsel to EMC Corporation, a
Massachusetts corporation (the "Company"), and am issuing this opinion in
connection with the registration statement on Form S-4 (File No. 333-110017)
(the "Registration Statement") filed by the Company with the Securities and
Exchange Commission (the "Commission") for the purpose of registering under the
Securities Act of 1933, as amended (the "Securities Act"), the shares (the
"Shares") of common stock, par value $.01 per share, of the Company issuable
pursuant to and in connection with the Agreement and Plan of Merger dated as of
October 13, 2003 by and among the Company, Elite Merger Corporation and
Documentum, Inc. in exchange for the outstanding shares of common stock of
Documentum, Inc.

         In this connection, I have examined and am familiar with originals or
copies, certified or otherwise identified to my satisfaction, of: (i) the
Registration Statement; (ii) the Restated Articles of Organization, as amended,
of the Company; (iii) such records of the corporate proceedings of the Company
as I have deemed necessary or appropriate as a basis for the opinions set forth
herein; and (iv) such certificates of officers of the Company and others and
such other records and documents as I have deemed necessary or appropriate as a
basis for the opinion set forth herein.

         In my examination, I have assumed the legal capacity of all natural
persons, the genuineness of all signatures, the authenticity of all documents
submitted to me as originals, the conformity to original documents of all
documents submitted to me as certified, conformed or photostatic copies and the
authenticity of the originals of such copies. As to any facts material to the
opinion expressed herein which I have not independently established or verified,
I have relied upon statements and representations of other officers and
representatives of the Company and others.

         I am admitted to the Bar of The Commonwealth of Massachusetts and do
not purport to be an expert on, or express any opinion concerning, any law other
than the substantive law of The Commonwealth of Massachusetts.

         Based upon and subject to the foregoing, I am of the opinion that the
Shares have been duly authorized for issuance and, when issued and paid for in
accordance with the terms described in the Registration Statement, will be
validly issued, fully paid and nonassessable.

         I hereby consent to the filing of this opinion with the Commission as
an exhibit to the Registration Statement. In giving this consent, I do not
thereby admit that I am in the category of persons whose consent is required
under Section 7 of the Securities Act or the rules and regulations of the
Commission promulgated thereunder. The undersigned assumes no obligation to
revise or supplement this opinion letter should the laws of such jurisdiction be
changed after the date hereof by legislative action, judicial decision or
otherwise.

         This opinion is furnished by me, as Senior Vice President and General
Counsel to the Company, in connection with the filing of the Registration
Statement and is not to be used, circulated or quoted for any other purpose or
otherwise referred to or relied upon by any other person without the prior
express written permission of the Company other than in connection with the
offer and sale of Shares while the Registration Statement is in effect.



                               Very truly yours,


                               /s/ Paul T. Dacier
                               -----------------------------------------
                               Paul T. Dacier
                               Senior Vice President and General Counsel