EXHIBIT 5.1

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                       60 State Street . Boston, MA 02109
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                                    October 16, 2001

MicroStrategy Incorporated
1861 International Drive
McLean, Virginia 22102

     Registration Statement on Form S-3
     ----------------------------------

Ladies and Gentlemen:

   This opinion is furnished to you in connection with a Registration Statement
on Form S-3 (the "Registration Statement") to be filed with the Securities and
Exchange Commission (the "Commission") under the Securities Act of 1933, as
amended (the "Securities Act"), for the registration of an aggregate of
3,500,000 shares of the class A common stock, $.001 par value per share (the
"Shares"), of MicroStrategy Incorporated, a Delaware corporation (the
"Company"). All of the Shares are being registered on behalf of certain
stockholders of the Company (the "Selling Stockholders").

   We have acted as counsel for the Company in connection with the registration
of the Shares.  We have examined signed copies of the Registration Statement to
be filed with the Commission.  We have also examined and relied upon the minutes
of meetings of the stockholders and the Board of Directors of the Company as
provided to us by the Company, stock record books of the Company as provided to
us by the Company, the Certificate of Incorporation and By-Laws of the Company,
each as restated and/or amended to date, and such other documents as we have
deemed necessary for purposes of rendering the opinions hereinafter set forth.

   In our examination of the foregoing documents, we have assumed the
genuineness of all signatures, the authenticity of all documents submitted to us
as originals, the conformity to original documents of all documents submitted to
us as copies, the authenticity of the originals of such latter documents and the
legal competence of all signatories to such documents.

   Our opinion below, insofar as it relates to the Selling Stockholders' Shares
being fully paid, is based solely on a certificate of the President and Chief
Financial Officer of the Company confirming the Company's receipt of the
consideration called for by the applicable resolutions authorizing the issuance
of such Shares.

   We assume that the appropriate action will be taken, prior to the offer and
sale of the Shares, to register and qualify the Shares for sale under all
applicable state securities or "blue sky" laws.







Boston   New York   Princeton   Reston   Washington   London*  Munich*  Oxford*
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Hale and Dorr LLP is a Massachusetts Limited Liability Partnership and includes
       Professional Corporations   *an independent joint venture law firm


October 16, 2001
Page 2


   We express no opinion herein as to the laws of any state or jurisdiction
other than the state laws of the Commonwealth of Massachusetts, the General
Corporation Law of the state of Delaware and the federal laws of the United
States of America.


   Based upon and subject to the foregoing, we are of the opinion that the
Shares have been duly authorized and are validly issued, fully paid and
nonassessable.

   It is understood that this opinion is to be used only in connection with the
offer and sale of the Shares while the Registration Statement is in effect.

   Please note that we are opining only as to the matters expressly set forth
herein, and no opinion should be inferred as to any other matters.

   We hereby consent to the filing of this opinion with the Commission as an
exhibit to the Registration Statement in accordance with the requirements of
Item 601(b)(5) of Regulation S-K under the Securities Act and to the use of our
name therein and in the related prospectus under the caption "Legal Matters."
In giving such consent, we do not hereby admit that we are in the category of
persons whose consent is required under Section 7 of the Securities Act or the
rules and regulations of the Commission.


                                           Very truly yours,

                                           /s/ Hale and Dorr LLP

                                           HALE AND DORR LLP