Exhibit 5.1

                          [EMC Corporation Letterhead]

                                        May 21, 2001

EMC Corporation
35 Parkwood Drive
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-3 (the "Registration
Statement") being filed by the Company with the Securities and Exchange
Commission (the "Commission") on the date hereof for the purpose of registering
under the Securities Act of 1933, as amended (the "Securities Act"), and the
sale by certain selling stockholders of the Company, of up to an aggregate of
10,100,000 shares (the "Shares") of common stock, par value $.01 per share, of
the Company.

    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; (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 are 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.

    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