Registration No. 333-





                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                    FORM S-8
            REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933

                         FactSet Research Systems Inc.
             (Exact name of registrant as specified in its charter)

          Delaware                                       13-3362547
(State  or  other   jurisdiction            (I.R.S. Employer Identification No.)
of incorporation or organization)

                               One Greenwich Plaza
                          Greenwich, Connecticut 06830
                                 (203) 863-1500
              (Address of Principal Executive Offices) (Zip Code)

  The FactSet Research Systems Inc. 2000 Employee Stock Option Plan
                            (Full title of the plan)

                                 Ernest S. Wong
          Senior Vice President, Chief Financial Officer and Secretary
                          FactSet Research Systems Inc.
                               One Greenwich Plaza
                          Greenwich, Connecticut 06830
                    (Name and address of agent for service)
                                 (203) 863-1500
         (Telephone number, including area code, of agent for service)



                         CALCULATION OF REGISTRATION FEE
--------------------------------------------------------------------------------

  Title of     Amount to be   Proposed maximum   Proposed maximum    Amount of
securities to   registered     offering price   aggregate offering  registration
be registered                   per share (1)        price(1)           fee
--------------------------------------------------------------------------------
                                                        
Common Stock,
par value
$.01 per share  2,000,000         31.85         63,700,000          15,925
-------------------------------------------------------------------------------


(1) The price of $31.85  per  share,  which was the  average of the high and low
prices of Common Stock as reported in the New York Stock  Exchange  consolidated
reporting  system  on  March  8,  2001  is set  forth  solely  for  purposes  of
calculating  the  registration  fee pursuant to Rule 457(h) under the Securities
Act of 1933, as amended.





PART I INFORMATION REQUIRED IN THE SECTION 10(a) PROSPECTUS

Item 1. Plan Information.

Refer to Exhibit 4.5 on page 3.

Item 2. Registrant Information and Employee Plan Annual Information.

Not required to be filed with the Commission.

PART II INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3. Incorporation of Documents by Reference.

The following  documents filed with the Commission by FactSet  Research  Systems
Inc. (the "Company") are incorporated herein by reference as of their respective
dates:

(a) FactSet Research Systems Inc. Annual Report on Form 10-K for the fiscal year
ended August 31, 2000 (and the documents incorporated by reference therein).

(b) FactSet Research Systems Inc. Quarterly Report on Form 10-Q for the quarters
ended November 30, 2000 and the documents incorporated by reference therein).

(c) FactSet  Research  Systems Inc.  Proxy  Statement on Form 14A filed with the
Commission  on November 22, 1999 (and the  documents  incorporated  by reference
therein).

(d) FactSet Research Systems Inc. Quarterly Report on Form 10-Q for the quarters
ended November 30, 1999 (and the documents incorporated by reference therein).

(e) FactSet Research Systems Inc.  Registration Statement on Form S-1 (File No.
333-04238), filed with the Commission on June 26, 1996, containing a description
of the Common Stock.

All documents subsequently filed by the Company with the Commission pursuant to
Sections  13(a),  13(c), 14 and 15(d) of the Exchange Act, after the date hereof
and prior to the filing of a post-effective amendment,  which indicates that all
securities  offered  have been sold or which  deregisters  all  securities  then
remaining unsold, shall be deemed to be incorporated by reference and to be part
hereof from the date of filing such  documents.  Any  statement  contained  in a
document  incorporated  or  deemed  to be  incorporated  by  reference  in  this
Registration Statement shall be deemed to be modified or superseded for purposes
of this Registration  Statement to the extent that a statement  contained herein
or  in  any  subsequently  filed  document  that  also  is or  is  deemed  to be
incorporated by reference  herein  modifies or supersedes  such  statement.  Any
statement so modified or superseded  shall not be deemed,  except as so modified
or superseded, to constitute a part of this Registration Statement.

The Company will provide without charge to each person to whom a copy of this
Registration  Statement is  delivered,  upon the written or oral request of such
person, a copy of any or all of the documents  incorporated by reference (except
for exhibits  thereto unless  specifically  incorporated by reference  therein).
Requests  for such copies  should be directed  to the Chief  Financial  Officer,
FactSet  Research  Systems Inc.,  One Greenwich  Plaza,  Greenwich,  Connecticut
06830,(203)863-1500.





Item 4. Description of Securities.

The class of securities to be offered,  pursuant to this registration statement,
have  been  registered  under  Section  12 of the  Exchange  Act.  See  Item 3 -
Incorporation of Documents by Reference.

Item 5. Interest of Named Experts and Counsel.

The validity of the Common Stock offered hereby has been passed upon by Cravath,
Swaine & Moore. See Exhibit 5.

Item 6. Indemnification of Directors and Officers.

Information   relating  to   indemnification   of  directors   and  officers  is
incorporated  by  reference  herein from Item 14 of the  Company's  Registration
Statement on Form S-1 (No. 333-04238).

Item 7. Exemption from Registration Claimed.

Not applicable.

Item 8. Exhibits.

Exhibit
Number    Description

4.1       Restated Certificate of Incorporation (filed as Exhibit 3.1 to the
          Company's Registration Statement on Form S-1 (File  No.  333-04238)
          filed with the Commission on June 5, 1996).*

4.2       By-laws  (filed as Exhibit 3.2 to the  Company's  Quarterly  Report on
          Form 10-Q for the first quarter of fiscal year 1999).*

4.3       Description of the Company's Common Stock incorporated by reference to
          the Company's Registration Statement on Form S-1 (File No. 333-04238)
          filed with the Commission on June 26, 1996.*

4.4       Form of Security Common Stock (filed as Exhibit 4.1 to the Company's
          Registration Statement on Form S-1 (File No. 333-04238)
          filed with the Commission on June 26, 1996).*

4.5       FactSet Research Systems Inc. 2000 Employee Stock Option
          Plan (filed as Exhibit A to the Company's Proxy Statement on Form 14A
          filed with the Commission on November 22, 1999).*

5         Opinion of Cravath, Swaine & Moore.

23.1      Consent of PricewaterhouseCoopers LLP.






23.2     Consent of Cravath, Swaine & Moore (included in Exhibit 5).

24       Powers of Attorney (contained on signature page).

*Incorporated by reference.


Item 9. Undertakings.

(a) The undersigned registrant hereby undertakes:

        (1) To file, during any  period in which offers or sales are being made,
a  post-effective  amendment  to this  registration  statement  to  include  any
material  information  with respect to the plan of  distribution  not previously
disclosed  in  the  registration  statement  or  any  material  change  to  such
information in the registration statement.

        (2) That, for the purpose of determining any liability under the
Securities  Act  of  1933,  as  amended  (the  "Securities   Act"),   each  such
post-effective  amendment  shall be  deemed to be a new  registration  statement
relating to the securities offered therein,  and the offering of such securities
at that time shall be deemed to be the initial bona fide offering thereof.

        (3) To remove from  registration by means of a post-effective  amendment
any of the securities being registered which remain unsold at the termination of
the offering.

(b) The  undersigned  registrant  hereby  undertakes  that,  for the purposes of
determining  any liability  under the Securities Act of 1933, each filing of the
registrant's  annual  report  pursuant to Section  13(a) or Section 15(d) of the
Securities  Exchange  Act of 1934  (and,  where  applicable,  each  filing of an
employee  benefit  plan's  annual  report  pursuant  to  Section  15(d)  of  the
Securities  Exchange  Act of 1934)  that is  incorporated  by  reference  in the
registration  statement  shall  be  deemed  to be a new  registration  statement
relating to the securities offered therein,  and the offering of such securities
at that time shall be deemed to be the initial bona fide offering thereof.

c) Insofar as indemnification  for liabilities  arising under the Securities Act
of 1933 may be permitted to directors,  officers and controlling  persons of the
registrant pursuant to the foregoing  provisions,  or otherwise,  the registrant
has been advised that in the opinion of the Securities  and Exchange  Commission
such indemnification is against public policy as expressed in the Securities Act
and is,  therefore,unenforceable.  In the event that a claim for indemnification
against such  liabilities  (other than the payment by the registrant of expenses
incurred or paid by a director,  officer or controlling person of the registrant
in the successful defense of any action, suit or proceeding) is asserted by such
director,  officer or controlling person in connection with the securities being
registered, the registrant will, unless in the opinion of its counsel the matter
has been  settled by  controlling  precedent,  submit to a court of  appropriate
jurisdiction the question whether such  indemnification  by it is against public
policy as expressed in the Act and will be governed by the final adjudication of
such issue.



SIGNATURES

Pursuant to the  requirements  of the  Securities  Act of 1933,  the  registrant
certifies  that it has  reasonable  grounds to believe  that it meets all of the
requirements  for filing on the Form S-8 and has duly caused  this  registration
statement  to  be  signed  on  its  behalf  by  the  undersigned,thereunto  duly
authorized in the City of Greenwich,  State of  Connecticut, on this 12th day of
March, 2001.

                                   FACTSET RESEARCH SYSTEMS INC.
                                   by    /s/ Ernest S. Wong
                                     -----------------------------
                                     Ernest S. Wong
                                     Senior Vice President, Chief Financial
                                     Officer and Secretary

Each person whose  signature  appears below appoints Ernest S. Wong, as his true
and lawful  attorney-in-fact  and agent,  with full  power of  substitution  and
resubstitution,  for  him  and in his  name,  place  and  stead,  in any and all
capacities, to sign any and all amendments (including post-effective amendments)
to this Registration Statement,  and to file the same, with all exhibits thereto
and all  other  documents  in  connection  therewith,  with the  Securities  and
Exchange  Commission,  granting unto said  attorney-in-fact and agent full power
and authority to do and perform each and every act and anything  appropriate  or
necessary  to be done,  as fully and for all intents and purposes as he might or
could  do  in  person,   hereby   ratifying   and   confirming   all  that  said
attorney-in-fact  and agent or his substitute or substitutes  may lawfully do or
cause to be done by virtue hereof.

Pursuant to the  requirements of the Securities Act of 1933,  this  Registration
Statement has been signed by the following  persons in the capacities and on the
dates indicated.

    Signature                         Title                          Date

                              Chairman of the Board of            March 12, 2001
/s/ Philip A. Hadley          Directors and Chief
------------------------      Executive Officer
Philip A. Hadley

/s/ Charles J. Snyder         Vice Chairman of the Board          March 12, 2001
------------------------      of Directors
Charles J. Snyder

/s/ Michael F. DiChristina    President Chief Operating           March 12, 2001
------------------------      Officer and Director
Michael F. DiChristina

/s/ Ernest S. Wong            Senior Vice President, Chief        March 12, 2001
------------------------      Financial Officer and Secretary
Ernest S. Wong

/s/ Scott A. Billeadeau       Director                            March 12, 2001
------------------------
Scott A. Billeadeau

/s/ John D. Connolly          Director                            March 12, 2001
------------------------
John D. Connolly

/s/ Joseph E. Laird, Jr.      Director                            March 12, 2001
------------------------
Joseph E. Laird, Jr.

/s/ John C. Mickle            Director                            March 12, 2001
------------------------
John C. Mickle

/s/ Walter F. Siebecker       Director                            March 12, 2001
------------------------
Walter F. Siebecker

/s/ Howard E. Wille            Director                           March 12, 2001
------------------------
Howard E. Wille





                                  EXHIBIT INDEX

Exhibit
Number         Description

4.1            Restated Certificate of Incorporation (filed as Exhibit 3.1 to
               the Company's Registration Statement on Form S-1 (File
               No.333-04238) filed with the Commission on June 5, 1996).*

4.2            By-laws (filed as Exhibit 3.2 to the Company's  Quarterly  report
               on Form 10-Q for the first quarter fiscal year 1999).*

4.3            Description of the Company's Common Stock incorporated by
               reference to the Company's Registration Statement on Form S-1
               (File No. 333-04238) filed with the Commission on June 26, 1996.*

4.4            Form of Common Stock (filed as Exhibit 4.1 to the Company's
               Registration Statement on Form S-1 (File No. 333-04238) filed
               with the Commission on June 26, 1996).*

4.5            FactSet Research Systems Inc. 2000 Employee Stock
               Option Plan (filed as Exhibit A to the Company's Proxy Statement
               on Form 14A filed with the Commission on November 22, 1999).*

5              Opinion of Cravath, Swaine & Moore.

23.1           Consent of PricewaterhouseCoopers LLP.

23.2           Consent of Cravath, Swaine & Moore (included in Exhibit 5).

24             Powers of Attorney (contained on signature page).

---------------
* Incorporated by reference.






                                                                    EXHIBIT 5
                                 [Letterhead of]
                             CRAVATH, SWAINE & MOORE

                                                                   March 9, 2001

                          FactSet Research Systems Inc.
                         Form S-8 Registration Statement


Ladies and Gentlemen:

We have  acted  as  counsel  for  FactSet  Research  Systems  Inc.,  a  Delaware
corporation  (the "Company"),  in connection with the Registration  Statement on
Form S-8 (the "Registration  Statement") being filed by the Company on March 12,
2001, with the Securities and Exchange  Commission (the "Commission")  under the
Securities  Act of 1933,  as amended  (the  "Securities  Act"),  with respect to
2,000,000  shares of Common Stock, par value $.01 per share, of the Company (the
"Common Stock"), which may be issued pursuant to the 2000 Employees Stock Option
Plan (the "Plan").

In  connection  with  the  foregoing,  we have  examined  originals,  or  copies
certified  or  otherwise  identified  to our  satisfaction,  of such  documents,
corporate  records  and  other  instruments  as  we  have  deemed  necessary  or
appropriate for the purpose of this opinion.

Based upon the  foregoing,  we are of opinion  that the Common  Stock is validly
authorized  and, when issued under the Plan in accordance with the terms thereof
for  consideration  having a value not less than the par value thereof,  will be
legally issued, fully paid and nonassessable.

We  hereby  consent  to  the  filing  of  this  opinion  as an  exhibit  to  the
Registration  Statement. In giving this consent, we do not thereby admit that we
are within 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.


                                   Very truly yours,

                                   /s/ Cravath, Swaine & Moore

FactSet Research Systems Inc.
One Greenwich Plaza
Greenwich, CT 06830








                                                                    EXHIBIT 23.1

                       CONSENT OF INDEPENDENT ACCOUNTANTS



We  hereby  consent  to the  incorporation  by  reference  in this  Registration
Statement on Form S-8 of our report dated  September  11, 2000,  relating to the
financial  statements,  which  appears on page 40 of the 2000  Annual  Report to
Shareholders  of  FactSet  Research  Systems  Inc.,  which  is  incorporated  by
reference in FactSet  Research  System Inc.'s Annual Report on Form 10-K for the
year ended August 31, 2000.


/s/ PRICEWATERHOUSECOOPERS LLP
PRICEWATERHOUSECOOPERS LLP

New York, New York
March 9th, 2001