
<PAGE>
 
================================================================================
 
 
 
 
                      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:  April 24, 1998
                       (Date of earliest event reported)
 
 
                           KILROY REALTY CORPORATION
            (exact name of registrant as specified in its charter)
 
<TABLE>
<CAPTION>  
<S>                                 <C>                                <C>
            MARYLAND                     COMMISSION FILE:                95-4598246
  (State or other jurisdiction              1-12675           (I.R.S. Employer Identification No.)
       of incorporation or                                                               
          organization)
 
</TABLE> 
 
 
 
 
                          2250 EAST IMPERIAL HIGHWAY
                                  SUITE 1200
                         EL SEGUNDO, CALIFORNIA  90245
         (Address of Principal executive offices, including zip code)
 
 
 
                                (310) 563-5500
             (Registrant's telephone number, including area code)
 
 
================================================================================
 
<PAGE>
 
ITEM 5.   OTHER EVENTS

     On April 24, 1998, Kilroy Realty Corporation (the "Registrant") completed a
public offering of 740,741 shares of its common stock, par value $.01 per share,
resulting in net proceeds to the Registrant of approximately $19.0 million.




                                       2
<PAGE>
 
ITEM 7.  FINANCIAL STATEMENT AND EXHIBITS.

     (c) Exhibits


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<CAPTION>

Exhibit 
  No.                               Description
-------                             -----------                     
<S>                  <C>
1.1                  Underwriting Agreement, dated as of April 21,
                     1998, by and among Kilroy Realty Corporation,
                     Kilroy Realty, L.P. and A.G. Edwards & Sons.
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                                       3
<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 hereunto duly authorized.


                                 KILROY REALTY CORPORATION



Date:  April 24, 1998            By /s/ ANN MARIE WHITNEY
                                 ---------------------------------------      
                                 Name: Ann Marie Whitney
                                 Title: Vice President and Controller

                                       4
<PAGE>
 
                                 EXHIBIT INDEX


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<CAPTION>
                                                                              Sequentially
Exhibit                                                                         Numbered 
  No.                            Description                                      Page
-------                          -----------                                 -------------           
<S>                              <C>                                         <C>
1.1                              Underwriting Agreement, dated
                                 as of April 21, 1998, by and
                                 among Kilroy Realty
                                 Corporation, Kilroy Realty,
                                 L.P. and A.G. Edwards & Sons, Inc.
</TABLE>

                                     II-1
