UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549


                                  FORM 12b-25


                           NOTIFICATION OF LATE FILING

                          Commission File Number 1-8383


(Check one): [X] Form 10-K [ ] Form 20-F [ ] Form 11-K [ ] Form 10-Q
             [ ] Form N-SAR [ ] Form N-CSR

                 For Period Ended: December 31, 2003
                 [ ] Transition Report on Form 10-K
                 [ ] Transition Report on Form 20-F
                 [ ] Transition Report on Form 11-K
                 [ ] Transition Report on Form 10-Q
                 [ ] Transition Report on Form N-SAR
                 For the Transition Period Ended: ______________________________

         Read Instructions Before Preparing Form. Please Print or Type.

NOTHING  IN THIS  FORM  SHALL BE  CONSTRUED  TO IMPLY  THAT THE  COMMISSION  HAS
VERIFIED ANY INFORMATION CONTAINED HEREIN.


If the notification  relates to a portion of the filing checked above,  identify
the Item(s) to which the notification relates:


PART I -- REGISTRANT INFORMATION

Mission West Properties, Inc.
--------------------------------------------------------------------------------
Full Name of Registrant

N/A
--------------------------------------------------------------------------------
Former Name if Applicable

10050 Bandley Drive
--------------------------------------------------------------------------------
Address of Principal Executive Office (Street and Number)

Cupertino, CA 95014
--------------------------------------------------------------------------------
City, State and Zip Code



PART II -- RULES 12b-25(b) AND (c)

If the subject report could not be filed without  unreasonable effort or expense
and the registrant seeks relief pursuant to Rule 12b-25(b), the following should
be completed. (Check box if appropriate)


[X]  (a) The  reason  described  in  reasonable  detail in Part III of this form
     could not be eliminated without unreasonable effort or expense

[ ]  (b) The subject  annual report,  semi-annual  report,  transition report on
     Form 10-K,  Form  20-F,  Form 11-K,  Form N-SAR or Form  N-CSR,  or portion
     thereof,  will be filed on or before the  fifteenth  calendar day following
     the  prescribed  due date;  or the subject  quarterly  report or transition
     report on Form  10-Q,  or portion  thereof,  will be filed on or before the
     fifth calendar day following the prescribed due date; and

[ ]  (c)  The  accountant's   statement   or  other  exhibit  required  by  Rule
     12b-25(c) has been attached if applicable.







PART III -- NARRATIVE

State below in reasonable detail why Forms 10-K, 20-F, 11-K, 10-Q, N-SAR, N-CSR,
or the  transition  report or  portion  thereof,  could not be filed  within the
prescribed time period.

(Attach extra sheets if needed)

The Registrant's Annual Report on Form 10-K for the year ended December 31, 2003
could not be filed within the  prescribed  time period  because its  independent
accountant,  PricewaterhouseCoopers  LLP,  San  Francisco,  California  ("PWC"),
previously engaged as the principal accountant to audit the financial statements
of Mission West  Properties,  Inc.,  (the  "Company"),  resigned as  independent
auditors  for the  Company on January  26,  2004.  PWC did not issue a report of
independent  auditors' with respect to the Company's  2003 financial  statements
prior to its  resignation.  On February 12, 2004,  PWC informed the Company that
PWC's audit reports dated January 21, 2002 and January 28, 2003 on the financial
statements of the Company for the years ended December 31, 2001 and December 31,
2002 should no longer be relied upon. The Audit Committee of the Company's board
of directors has retained independent counsel to investigate matters asserted by
PWC  subsequent  to its  resignation.  The  Company  is  unable  to  retain  new
independent accountants until that investigation has been concluded.  Hence, the
Company is unable to obtain  reports of  independent  auditors for the financial
statements for the years ended December 31, 2001, December 31, 2002 and December
31, 2003 at this time.

PART IV -- OTHER INFORMATION

(1)  Name  and  telephone  number  of  person  to  contact  in  regard  to  this
     notification

       Carl E. Berg                   408                       725-0700
-------------------------   ------------------------   -------------------------
          (Name)                   (Area Code)            (Telephone Number)

(2)  Have all other periodic  reports  required under Section 13 or 15(d) of the
     Securities Exchange Act of 1934 or Section 30 of the Investment Company Act
     of 1940 during the preceding 12 months or for such shorter  period that the
     registrant  was required to file such  report(s)  been filed ? If answer is
     no, identify report(s).                                      Yes [X] No [ ]

(3)  Is it anticipated that any significant change in results of operations from
     the corresponding  period for the last fiscal year will be reflected by the
     earnings  statements  to be  included  in the  subject  report  or  portion
     thereof?                                                       Yes[ ] No[X]

     If so, attach an explanation of the anticipated  change,  both  narratively
     and quantitatively, and, if appropriate, state the reasons why a reasonable
     estimate of the results cannot be made.

                          MISSION WEST PROPERTIES, INC.
                  --------------------------------------------
                  (Name of Registrant as Specified in Charter)



has  caused  this  notification  to be signed on its  behalf by the  undersigned
hereunto duly authorized.

Date  March 16, 2004                             By  /s/ Carl E. Berg
     -----------------------                        ----------------------------
                                                     Carl E. Berg
                                                     Chief Executive Officer