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):

                                February 24, 1998



                        TRUSTED INFORMATION SYSTEMS, INC.
             (Exact name of registrant as specified in its charter)



     Delaware                    000-21067                      51-0375640
(State of Incorporation)  (Commission File Number)            (IRS Employer
                                                           Identification No.)




                       3060 Washington Boulevard (Rt. 97)
                            Glenwood, Maryland 21738
               (Address of principal executive offices) (Zip Code)



                                 (301) 854-6889
                         (Registrant's telephone number)



                                       1
<PAGE>


Item 5.  Other Events.

     On February 23, 1998, Networks Associates,  Inc. ("Network Associates") and
Trusted Information Systems,  Inc. ("TIS") announced that they have entered into
an  Agreement  and Plan of Merger  dated as of February  22,  1998 (the  "Merger
Agreement"),  which is filed herewith, pursuant to which Thor Acquisition Corp.,
a wholly-owned  subsidiary of Network  Associates,  will merge with and into TIS
(the "Merger").

     Under the terms of the  Merger  Agreement,  each  outstanding  share of TIS
common stock will be exchanged for .323 of a share of Network  Associates common
stock,  outstanding  TIS stock options will be exchanged for Network  Associates
stock  options  (adjusted  for  the  exchange  ratio)  and  TIS  will  become  a
wholly-owned subsidiary of Network Associates. The transaction will be accounted
for as a pooling of interests.  The Merger,  which is expected to be consummated
within  60 to 90 days of the  date  hereof,  is  subject  to  customary  closing
conditions,  regulatory  approvals and the approval of the  shareholders of TIS.
Pending  filing and clearance of requisite  proxy  materials with the Securities
and Exchange Commission, TIS has not yet set a date for a special meeting of its
shareholders to approve the merger.

     In connection  with the Merger  Agreement,  Stephen T. Walker and Martha A.
Branstad  (both  directors  and  the  two  largest   stockholders  of  TIS  with
approximately  32% of TIS'  currently  outstanding  common  stock)  entered into
Voting Agreements pursuant to which they agreed,  among other things, to vote in
favor of the Merger.  In addition,  the Company granted to Network  Associates a
stock  option to  acquire  up to 19.9% of TIS'  outstanding  common  stock at an
axercise price of $20 per share,  payable in cash or Network  Associates  common
stock.  During  its  term,  the  option  is  exerciseable,  in whole or in part,
immediately  prior to  consummation  of certain  change of control  transactions
inolving TIS and parties other than Network Associates.

     Network  Associates  and TIS issued a joint press  release  announcing  the
Merger on February  23,  1998,  which is filed  herewith as Exhibit  99.1 and is
incorporated herein by reference.

Item 7.  Financial Statements, Pro Forma Financial Information and Exhibits.

(c) Exhibits.

2.1  Agreement and Plan of Merger dated  February 22, 1998 by and among Networks
     Associates,  Inc., Thor Acquisition Corp. and Trusted Information  Systems,
     Inc.*

99.1 Joint press release of Networks  Associates,  Inc. and Trusted  Information
     Systems, Inc. dated December 1, 1997.



* The Registrant will supply the Securities and Exchange Commission upon request
with copies of any  exhibit or  Schedule  to Exhibit  2.1 which is not  included
herein.



                                       2
<PAGE>



                                   SIGNATURES


         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.


Date:  February 24, 1998            Trusted Information Systems, Inc.



                                    /s/ Stephen T. Walker
                                    By:       Stephen T. Walker
                                    Title:    Chief Executive Officer




                                       3
<PAGE>


                                  EXHIBIT INDEX


2.1  Agreement and Plan of Merger dated  February 22, 1998 by and among Networks
     Associates,  Inc., Thor Acquisition Corp. and Trusted Information  Systems,
     Inc.*

99.1 Joint press release of Networks  Associates,  Inc. and Trusted  Information
     Systems, Inc. dated February 23, 1998.



* The Registrant will supply the Securities and Exchange Commission upon request
with copies of any  exhibit or  Schedule  to Exhibit  2.1 which is not  included
herein.




                                       4
<PAGE>
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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):

                                February 24, 1998

                        TRUSTED INFORMATION SYSTEMS, INC.
             (Exact name of registrant as specified in its charter)

     Delaware                    000-21067                      51-0375640
(State of Incorporation)  (Commission File Number)            (IRS Employer
                                                           Identification No.)

                       3060 Washington Boulevard (Rt. 97)
                            Glenwood, Maryland 21738
               (Address of principal executive offices) (Zip Code)

                                 (301) 854-6889
                         (Registrant's telephone number)

                                       1
Item 5.  Other Events.

     On February 23, 1998, Networks Associates,  Inc. ("Network Associates") and
Trusted Information Systems,  Inc. ("TIS") announced that they have entered into
an  Agreement  and Plan of Merger  dated as of February  22,  1998 (the  "Merger
Agreement"),  which is filed herewith, pursuant to which Thor Acquisition Corp.,
a wholly-owned  subsidiary of Network  Associates,  will merge with and into TIS
(the "Merger").

     Under the terms of the  Merger  Agreement,  each  outstanding  share of TIS
common stock will be exchanged for .323 of a share of Network  Associates common
stock,  outstanding  TIS stock options will be exchanged for Network  Associates
stock  options  (adjusted  for  the  exchange  ratio)  and  TIS  will  become  a
wholly-owned subsidiary of Network Associates. The transaction will be accounted
for as a pooling of interests.  The Merger,  which is expected to be consummated
within  60 to 90 days of the  date  hereof,  is  subject  to  customary  closing
conditions,  regulatory  approvals and the approval of the  shareholders of TIS.
Pending  filing and clearance of requisite  proxy  materials with the Securities
and Exchange Commission, TIS has not yet set a date for a special meeting of its
shareholders to approve the merger.

     In connection  with the Merger  Agreement,  Stephen T. Walker and Martha A.
Branstad  (both  directors  and  the  two  largest   stockholders  of  TIS  with
approximately  32% of TIS'  currently  outstanding  common  stock)  entered into
Voting Agreements pursuant to which they agreed,  among other things, to vote in
favor of the Merger.  In addition,  the Company granted to Network  Associates a
stock  option to  acquire  up to 19.9% of TIS'  outstanding  common  stock at an
axercise price of $20 per share,  payable in cash or Network  Associates  common
stock.  During  its  term,  the  option  is  exerciseable,  in whole or in part,
immediately  prior to  consummation  of certain  change of control  transactions
inolving TIS and parties other than Network Associates.

     Network  Associates  and TIS issued a joint press  release  announcing  the
Merger on February  23,  1998,  which is filed  herewith as Exhibit  99.1 and is
incorporated herein by reference.

Item 7.  Financial Statements, Pro Forma Financial Information and Exhibits.

(c) Exhibits.

2.1  Agreement and Plan of Merger dated  February 22, 1998 by and among Networks
     Associates,  Inc., Thor Acquisition Corp. and Trusted Information  Systems,
     Inc.*

99.1 Joint press release of Networks  Associates,  Inc. and Trusted  Information
     Systems, Inc. dated December 1, 1997.

* The Registrant will supply the Securities and Exchange Commission upon request
with copies of any  exhibit or  Schedule  to Exhibit  2.1 which is not  included
herein.

                                       2
SIGNATURES

         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.

Date:  February 24, 1998            Trusted Information Systems, Inc.

                                    /s/ Stephen T. Walker
                                    By:       Stephen T. Walker
                                    Title:    Chief Executive Officer

                                       3
EXHIBIT INDEX

2.1  Agreement and Plan of Merger dated  February 22, 1998 by and among Networks
     Associates,  Inc., Thor Acquisition Corp. and Trusted Information  Systems,
     Inc.*

99.1 Joint press release of Networks  Associates,  Inc. and Trusted  Information
     Systems, Inc. dated February 23, 1998.

* The Registrant will supply the Securities and Exchange Commission upon request
with copies of any  exhibit or  Schedule  to Exhibit  2.1 which is not  included
herein.

                                       4