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)  September 24, 1998
                                                  ------------------------------


                            INTEGRATED SYSTEMS, INC.
- --------------------------------------------------------------------------------
             (Exact name of registrant as specified in its charter)


         California                   0-18268                 94-2658153
- ----------------------------        -----------             ----------------
(State or other jurisdiction        (Commission             (I.R.S. Employer
      of incorporation)             File Number)           Identification No.)


          3260 Jay Street
       Santa Clara, California                                95054-3309
- ----------------------------------------                      ----------
(Address of principal executive offices)                      (Zip Code)


Registrant's telephone number, including area code        (408) 980-1500
                                                   -----------------------------



Item 5:           Other Events

                  Adoption of Stockholder Rights Plan.

                  On September  24, 1998,  the Board of Directors of  Integrated
Systems,  Inc.  (the  "Company")  declared a  dividend  of one  preferred  share
purchase right (a "Right") for each  outstanding  share of common stock,  no par
value  (the  "Common  Shares"),  of the  Company.  The  dividend  is  payable to
stockholders of record on October 15, 1998 (the "Record Date"). In addition, one
Right  shall be issued  with each  Common  Share that  becomes  outstanding  (i)
between  the  Record  Date  and  the  earliest  of the  Distribution  Date,  the
Redemption Date and the Final  Expiration Date (as such terms are defined in the
Rights  Agreement)  or (ii)  following  the  Distribution  Date and prior to the
Redemption  Date or Final  Expiration  Date,  pursuant to the  exercise of stock
options  or  under  any  employee  plan or  arrangement  or upon  the  exercise,
conversion  or exchange of other  securities  of the Company,  which  options or
securities were outstanding prior to the Distribution  Date. Each Right entitles
the registered  holder to purchase from the Company one two-hundredth of a share
of Series A Junior  Participating  Preferred Stock, no par value (the "Preferred
Shares"),  of the  Company,  at a price of $55.00,  subject to  adjustment.  The
description  and terms of the  Rights are set forth in a Rights  Agreement  (the
"Rights Agreement") between the Company and ChaseMellon Shareholder Services, as
Rights  Agent.  A summary  of the Rights and Rights  Agreement  is  included  as
Exhibit C to the Rights Agreement, which is included as Exhibit 4.1 hereto.







Item 7:           Financial Statements and Exhibits.

                  (c)      Exhibits
                           --------

                           4.1      Rights  Agreement  dated September 30, 1998,
                                    between   the   Company   and    ChaseMellon
                                    Shareholder Services, as Rights Agent, which
                                    includes   as   Exhibit   A  the   form   of
                                    Certificate of  Determination of Preferences
                                    of Series A Junior  Participating  Preferred
                                    Stock,  as  Exhibit  B  the  Form  of  Right
                                    Certificate  and as Exhibit C the Summary of
                                    Rights   to   Purchase   Preferred   Shares.
                                    (Incorporated  by reference to the Company's
                                    Registration  Statement  on Form  8-A  filed
                                    with the Securities and Exchange  Commission
                                    on October 6, 1998.)

                           99.1     Press release of the Company dated September
                                    30, 1998.






                                    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 hereunto duly authorized.

Dated:  October 6, 1998

                                           INTEGRATED SYSTEMS, INC.



                                           By: /s/ Joseph Addiego
                                               --------------------------------
                                               Joseph Addiego
                                               Chief Executive Officer








                                  EXHIBIT INDEX


Exhibit
- -------

4.1               Rights Agreement dated September 30, 1998, between the Company
                  and ChaseMellon  Shareholder  Services, as Rights Agent, which
                  includes as Exhibit A the form of Certificate of Determination
                  of  Preferences  of  Series A Junior  Participating  Preferred
                  Stock,  as  Exhibit  B the  Form of Right  Certificate  and as
                  Exhibit C the Summary of Rights to Purchase  Preferred Shares.
                  (Incorporated  by  reference  to  the  Company's  Registration
                  Statement on Form 8-A filed with the  Securities  and Exchange
                  Commission on October 6, 1998.)

99.1              Press release of the Company dated September 30, 1998.