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                       SECURITIES AND EXCHANGE COMMISSION

                             WASHINGTON, D.C. 20549


                                 ---------------

                                    FORM 8-K

                                 CURRENT REPORT

                     PURSUANT TO SECTION 13 OR 15(d) OF THE

                         SECURITIES EXCHANGE ACT OF 1934





Date of Report (Date of earliest event reported) NOVEMBER 18, 1998



                          CORSAIR COMMUNICATIONS, INC.
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               (Exact name of registrant as specified in charter)



         DELAWARE                      0-25356                   77-0390406
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(State of other jurisdiction         (Commission               (IRS Employer 
       of incorporation)             File Number)            Identification No.)



3408 HILLVIEW AVENUE, PALO ALTO, CALIFORNIA                        94304
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(Address of principal executive offices)                         (Zip Code)


Registrant's telephone number, including area code  (650) 842-3300



                                      NONE
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          (Former name or former address, if changed since last report)



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Item 5.  Other Events.

                  On November 18, 1998, the Board of Directors of Corsair
Communications, Inc. (the "Company") declared a dividend of one preferred share
purchase right (a "Right") for each outstanding share of Common Stock (the
"Common Stock"), par value $.001 per share, of the Company. The dividend is
payable on December 4, 1998 (the "Record Date") to the stockholders of record on
that date. Each Right entitles the registered holder to purchase from the
Company one one-thousandth of a share (a "Unit") of Series A Junior
Participating Preferred Stock, par value $.001 per share (the "Series A
Preferred Stock"), of the Company at a price of $40.00 per Unit (the "Purchase
Price"), subject to adjustment. The description and terms of the Rights are set
forth in a Rights Agreement dated as of November 18, 1998 (the "Rights
Agreement") between the Company and Bank Boston N.A., as Rights Agent (the
"Rights Agent").

                  Until the earlier to occur of (i) the close of business on the
first date of a public announcement that a person or group of affiliated or
associated persons (an "Acquiring Person") have acquired beneficial ownership of
15% or more of the outstanding Common Stock or (ii) 10 business days (or such
later date as may be determined by action of the Board of Directors prior to
such time as any Person becomes an Acquiring Person) following the commencement
of, or announcement of an intention to make, a tender offer or exchange offer
the consummation of which would result in the beneficial ownership by a person
or group of 15% or more of such outstanding Common Stock (the earlier of such
dates being called the "Distribution Date"), the Rights will be evidenced, with
respect to any of the Common Stock certificates outstanding as of the Record
Date, by such Common Stock certificate with a copy of this Summary of Rights
attached thereto.

                  The Rights Agreement provides that, until the Distribution
Date, the Rights will be transferred with and only with the Common Stock. Until
the Distribution Date (or earlier redemption or expiration of the Rights), new
Common Stock certificates issued after the Record Date, upon transfer or new
issuance of Common Stock will contain a notation incorporating the Rights
Agreement by reference. Until the Distribution Date (or earlier redemption or
expiration of the Rights), the surrender for transfer of any certificates for
Common Stock, outstanding as of the Record Date, even without such notation or a
copy of this Summary of Rights being attached thereto, will also constitute the
transfer of the Rights associated with the Common Stock represented by such
certificate. As soon as practicable following the Distribution Date, separate
certificates evidencing the Rights ("Rights Certificates") will be mailed to
holders of record of the Common Stock as of the Close of Business on the
Distribution Date and such separate Rights Certificates alone will evidence the
Rights.

                  The Rights are not exercisable until the Distribution Date.
The Rights will expire at the close of business on November 18, 2008, (the
"Final Expiration Date"), unless the Final Expiration Date is extended or unless
the Rights are earlier redeemed or exchanged by the Company, in each case as
described below.

                  The Purchase Price payable, and the number of Units of Series
A Preferred Stock or other securities or property issuable, upon exercise of the
Rights are subject to adjustment from time to time to prevent dilution (i) in
the event of a stock dividend on, or a subdivision, combination or
reclassification of, the Series A Preferred Stock, (ii) upon the grant to
holders of the Units of Series A Preferred Stock of certain rights or warrants
to subscribe for or purchase Units of Series A Preferred Stock at a price, or
securities convertible into Units of Series A Preferred Stock with a conversion
price, less than the then current market price of the Units of Series A
Preferred Stock or (iii) upon the distribution to holders of the Units of Series
A Preferred Stock of evidences of indebtedness or assets (excluding regular
periodic cash dividends paid out of earnings or retained earnings or dividends
payable in Units of Series A Preferred Stock) or of subscription rights or
warrants (other than those referred to above).

                  The number of outstanding Rights and the number of Units of
Series A Preferred Stock issuable upon exercise of each Right are also subject
to adjustment in the event of a stock split of the Common Stock or a stock
dividend on the Common Stock payable in Common Stock or subdivisions,
consolidations or combinations of the Common Stock occurring, in any such case,
prior to the Distribution Date.

                  Units of Preferred Stock purchasable upon exercise of the
Rights will not be redeemable. Each Unit of Preferred Stock will be entitled to
a dividend equal to any dividend declared per share of Common Stock. In the
event of liquidation, each Unit of Preferred Stock will be entitled to a payment
equal to any payment made per 



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share of Common Stock. Each Unit of Preferred Stock will have one vote, voting
together with the Common Stock. Finally, in the event of any merger,
consolidation or other transaction in which shares of Common Stock are
exchanged, each Unit of Preferred Stock will be entitled to receive an amount
equal to the amount received per share of Common Stock. These rights are
protected by customary antidilution provisions.

                  Because of the nature of the dividend, liquidation and voting
rights, and the value of the Series A Preferred Stock, the Units of Series A
Preferred Stock purchasable upon exercise of each Right should approximate the
value of one share of Common Stock.

                  In the event that, after the Rights become exercisable, the
Company is acquired in a merger or other business combination transaction with
an Acquiring Person or an affiliate thereof, or 50% or more of its consolidated
assets or earning power are sold to an Acquiring Person or an affiliate thereof,
proper provision will be made so that each holder of a Right will thereafter
have the right to receive, upon exercise thereof at the then current exercise
price of the Rights, that number of shares of common stock of the acquiring
company which at the time of such transaction will have a market value of two
times the exercise price of the Rights.

                  In the event that any person or group of affiliated or
associated persons becomes the beneficial owner of 15% or more of the
outstanding shares of Common Stock, proper provision shall be made so that each
holder of a Right, other than Rights beneficially owned by the Acquiring Person
(which will thereafter be void), will thereafter have the right to receive upon
exercise Units of Series A Preferred Stock (or cash, Common Stock, other
securities or property) having a market value of two times the exercise price of
the Rights.

                  At any time after the acquisition by a person or group of
affiliated or associated persons of beneficial ownership of 15% or more of the
outstanding shares of Common Stock and prior to the acquisition by such person
or group of 50% or more of the outstanding Common Stock, the Board of Directors
of the Company may exchange the Rights (other than Rights owned by such person
or group which have become void), in whole or in part, at an exchange ratio of
one Unit of Series A Preferred Stock (subject to adjustment) which shall equal,
subject to adjustment to reflect stock splits, stock dividends and similar
transactions occurring after the date hereof, that number obtained by dividing
the Purchase Price by the then current per share market price per Unit of Series
A Preferred Stock on the earlier of (i) the date on which any Person becomes an
Acquiring Person and (ii) the date on which a tender or exchange offer is
announced by any Person, if upon consummation thereof such Person would be the
Beneficial Owner of 15% or more of the shares of Company Common Stock then
outstanding.

                  With certain exceptions, no adjustment in the Purchase Price
will be required until cumulative adjustments require an adjustment of at least
1% in such Purchase Price. No fractional shares of Series A Preferred Stock will
be issued (other than fractions which are integral multiples of one
one-thousandth of a share of Series A Preferred Stock, which may, at the
election of the Company, be evidenced by depositary receipts) and, in lieu
thereof, an adjustment in cash will be made based on the market price of the
Units of Series A Preferred Stock on the last trading day prior to the date of
exercise.

                  At any time on or prior to the close of business on the first
date of a public announcement that a person or group of affiliated or associated
persons acquire beneficial ownership of 15% or more of the outstanding Common
Stock (unless the Board of Directors extends such ten-day period), the Board of
Directors of the Company may redeem the Rights in whole, but not in part, at a
price of $.001 per Right (the "Redemption Price"). The redemption of the rights
may be made effective at such time on such basis and with such conditions as the
Board of Directors in its sole discretion may establish. Immediately upon any
redemption of the Rights, the right to exercise the Rights will terminate and
the only right of the holders of Rights will be to receive the Redemption Price.
The Rights are also redeemable under other circumstances as specified in the
Rights Agreement.

                  The terms of the Rights may be amended by the Board of
Directors of the Company without the consent of the holders of the Rights except
that from and after a Distribution Date no such amendment may adversely affect
the interests of the holders of the Rights.

                  Until a Right is exercised, the holder thereof, as such, will
have no rights as a stockholder of the Company, including, without limitation,
the right to vote or to receive dividends.



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                  The Rights have certain anti-takeover effects. The Rights will
cause substantial dilution to a person or group that attempts to acquire the
Company on terms not approved by the Company's Board of Directors, except
pursuant to an offer conditioned on a substantial number of Rights being
acquired. The Rights should not interfere with any merger or other business
combination approved by the Board of Directors since the Rights may be redeemed
by the Company at the Redemption Price prior to the occurrence of a Distribution
Date.

                  The Rights Agreement, dated as of November 18, 1998 between
the Company and the Rights Agent, specifying the terms of the Rights, is
attached hereto as an exhibit and is incorporated herein by reference. The
foregoing description of the Rights is qualified in its entirety by reference to
such exhibit. The Certificate of Designation for the Series A Junior
Participating Preferred Stock is attached hereto as an exhibit. The foregoing
description of the Series A Junior Participating Preferred Stock is qualified in
its entirety by reference to such exhibit.

Item 7.  Financial Statements and Exhibits.

          Exhibit 4         Rights Agreement, dated as of November 18, 1998,
                            between the Company and Bank Boston N.A., which
                            includes the form of Certificate of Designation for
                            the Series A Junior Participating Preferred Stock as
                            Exhibit A, the form of Rights Certificate as Exhibit
                            B and the Summary of Rights to Purchase Series A
                            Preferred Shares as Exhibit C. Pursuant to the
                            Rights Agreement, printed Right Certificates will
                            not be mailed until as soon as practicable after the
                            earlier of (i) the close of business on the first
                            date of a public announcement that a person or group
                            has acquired beneficial ownership of 15% or more of
                            the shares of Common Stock or (ii) the tenth (10th)
                            business day (or such later date as may be
                            determined by action of the Board of Directors)
                            after a person commences, or announces its intention
                            to commence, a tender offer or exchange offer the
                            consummation of which would result in the beneficial
                            ownership by a person or group of 15% or more of the
                            shares of Common Stock.

          Exhibit 21(a)     Form of Letter to Stockholders of Corsair
                            Communications, Inc. regarding the adoption of the
                            Rights Plan pursuant to the Rights Agreement.



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                                    SIGNATURE

                  Pursuant to the requirements of the Securities Exchange Act of
1934, the Registrant has duly caused this report to be signed on its behalf by
the undersigned thereunto duly authorized.




                                       CORSAIR COMMUNICATIONS, INC.


DATE:  November 20, 1998               By: /s/  Mary Ann Byrnes
                                           -------------------------------------
                                           Name:  Mary Ann Byrnes
                                           Title: President and Chief Executive
                                                  Officer




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                                  EXHIBIT INDEX

  EXHIBIT
  NUMBER                              DOCUMENT DESCRIPTION
  -------                             --------------------
     4            Rights Agreement, dated as of November 18, 1998 between the
                  Company and Bank Boston N.A., which includes the form of
                  Certificate of Designation for the Series A Junior
                  Participating Preferred Stock as Exhibit A, the form of Rights
                  Certificate as Exhibit B and the Summary of Rights to Purchase
                  Series A Preferred Shares as Exhibit C. Pursuant to the Rights
                  Agreement, printed Right Certificates will not be mailed until
                  as soon as practicable after the earlier of (i) the close of
                  business on the first date of a public announcement that a
                  person or group has acquired beneficial ownership of 15% or
                  more of the shares of Common Stock or (ii) the tenth (10th)
                  business day (or such later date as may be determined by
                  action of the Board of Directors) after a person commences, or
                  announces its intention to commence, a tender offer or
                  exchange offer the consummation of which would result in the
                  beneficial ownership by a person or group of 15% or more of
                  the shares of Common Stock.

     21(a)        Form of Letter to Stockholders of Corsair Communications, Inc.
                  regarding the adoption of the Rights Plan pursuant to the 
                  Rights Agreement.