Exhibit 99.1


News Release

FOR IMMEDIATE RELEASE

FactSet is a registered trademark of FactSet Research Systems Inc.

Howard E. Wille to Retire as CEO of FactSet Research Systems

Co-Founder Charles J. Snyder Appointed Interim CEO


May 22, 2000,  (Greenwich,  CT)--FactSet  Research Systems Inc.,  (NYSE:  FDS) a
major supplier of  computer-based  financial and economic data to the investment
community,  today announced that Howard E. Wille,  72, has stepped down as Chief
Executive Officer of the Company.


Mr. Wille,  who has served as Chairman and Chief  Executive  since the Company's
formation in 1978, will remain Chairman of the Board of FactSet until the end of
the current fiscal year.


Charles J.  Snyder,  co-founder  of FactSet and Vice  Chairman of the  Company's
Board of  Directors,  has been named  interim CEO while an  executive  search is
conducted by the  Company's  Board of  Directors.  Michael F.  DiChristina  will
continue as President and Chief Operating Officer and will report to Mr. Snyder.


"I have spent the last 22 years  building and actively  managing  FactSet," said
Mr. Wille.  "However,  I believe that the time has come to reduce my role at the
Company,  thereby  allowing me to spend more time pursuing  personal  interests.
Chuck has been my partner at FactSet from the  beginning and will help guide the
Company in the coming months."


"I am proud of all that we have  accomplished,  and I am  pleased  to make  this
announcement  while the  Company is showing  robust  growth and  continued  high
profitability,"  continued Mr. Wille. "FactSet is well positioned to continue to
expand into new markets and create innovative services."


FactSet  Research  Systems Inc. is a leading  provider of global  financial  and
economic  information,  including  fundamental  data  on tens  of  thousands  of
companies  worldwide.  Combining  more than 100 databases into its own dedicated
online  service,  the company also  provides the tools to download,  combine and
manipulate the data for investment analysis.


The company, headquartered in Greenwich, Connecticut, was formed in 1978 and now
conducts  operations from nine locations  worldwide  including Boston, New York,
San Mateo, London, Tokyo, Hong Kong, and Sydney.