MISSION WEST PROPERTIES, INC.
                    10050 Bandley Drive, Cupertino, CA 95014
                        Ph. 408-725-0700 Fax 408-725-1626


November 1, 2005

Mr. Josh Forgione
Staff Accountant
United States Securities and Exchange Commission
100 F Street, N.E.
Washington, D.C. 20549

       Re: Mission West Properties, Inc.
       Response to Comments from the SEC on Form 10-K for Fiscal Year Ended
       December 31, 2004; and
       Forms 10-Q for the Fiscal Quarters ended March 31, 2005 and June 30, 2005
       File No. 0-25235

Dear Mr. Forgione:

This  letter  sets  forth  responses  of  Mission  West  Properties,  Inc.  (the
"Company") to your comments relating to the Company's Annual Report on Form 10-K
and Forms 10-Q  contained  in your  letter  dated  October 21,  2005.  The Staff
comment is  repeated  in  capitalized  letters  type  below,  and the  Company's
response appears immediately beneath each comment.

Form 10-K for the year ended December 31, 2004

ITEM 15, EXHIBITS,  FINANCIAL  STATEMENT SCHEDULES AND REPORTS ON FORM 8-K, PAGE
         88

     1.   SUPPLEMENTALLY ADVISE US AS TO WHY RAYMOND V. MARINO IS A SIGNATORY OF
          THE  CERTIFICATION  FILED UNDER ITEM  601(b)(31) OF REGULATION S-K BUT
          NOT THE CERTIFICATION FILED UNDER ITEM 601(b)(32) OF REGULATION S-K.

          Raymond V. Marino is a director, president and chief operating officer
          of the Company.  Carl E. Berg is chairman and chief executive  officer
          of the Company. Wayne Pham is vice president of finance and controller
          (principal accounting officer) of the Company. The certification filed
          under Item  601(b)(31) is made pursuant to Section 302 of the Sarbanes
          Oxley Act ("SOX"),  which requires that certifications be submitted by
          the  "principal  executive  officer  or  officers  and  the  principal
          financial  officer  or  officers,   or  persons   performing   similar
          functions."  As  disclosed  under Item 9A of the  Company's  2003 Form
          10-K,  the  Company's  auditors  identified  a  material  weakness  in
          internal  controls  attributable  to the  Company's low head count and
          segregation of duties  without  compensating  controls.  One important
          measure  recommended  by  the  auditors  to  remediate  this  internal
          weakness



          was to involve the Company's  president and chief  operating  officer,
          Mr.  Marino,  in the review of the  Company's  internal  controls  and
          procedures. The Company accepted that recommendation and, as a result,
          Mr.  Marino  became one of the officers  required to sign and submit a
          certification under SOX Section 302.

          The certification  filed under Item 601(b)(32) is made pursuant to SOX
          Section 906,  which requires that  certifications  be submitted by the
          "chief  executive  officer and chief financial  officer (or equivalent
          thereof) of the issuer." Mr. Marino does not hold either  position and
          hence has not submitted this additional certification.

     2.   THE CERTIFICATIONS MUST COMPLY WITH THE SIGNATURE REQUIREMENTS OF RULE
          302 OF REGULATION  S-T. PLEASE AMEND YOUR FORM 10-K AND FORMS 10-Q FOR
          THE  QUARTERS  ENDED  MARCH  31,  2005  AND JUNE  30,  2005,  IN THEIR
          ENTIRETY,  TO INCLUDE  NEW  CERTIFICATIONS  THAT  CONTAINED  CONFORMED
          SIGNATURES IN ACCORDANCE WITH RULE 302 OF REGULATION S-T.

          We will file a Form  10-K/A for the fiscal  year  ended  December  31,
          2004,  and Forms 10-Q/A for the quarters ended March 31, 2005 and June
          30,  2005,  in their  entirety,  to include  new  certifications  that
          contain conformed signatures in accordance with Rule 302 of Regulation
          S-T.

     3.   PLEASE CONFIRM TO US THAT YOU OBTAINED MANUALLY SIGNED  CERTIFICATIONS
          FROM EACH  SIGNATORY TO YOUR  CERTIFICATIONS  FILED AS EXHIBITS  31.1,
          31.2,  31.3 AND 32, AT THE TIME OF THE ORIGINAL  FILINGS IN ACCORDANCE
          WITH RULE 302 OF REGULATION S-T.

          We have obtained and maintain in the Company's  files manually  signed
          certifications  from each  signatory  to our  certifications  filed as
          exhibits 31.1,  31.2, 31.3 and 32, at the time of the original filings
          in accordance with Rule 302 of Regulation S-T.

     4.   THE LANGUAGE IN THE CERTIFICATIONS SHOULD NOT BE CHANGED FROM THAT SET
          FORTH  IN ITEM  601(b)(31)  OF  REGULATION  S-K.  PLEASE  REVISE  YOUR
          CERTIFICATIONS  FILED TO REFLECT THE LANGUAGE  EXACTLY AS SET FORTH IN
          ITEM 601(b)(31) OF REGULATION  S-K. PLEASE MAKE CONFORMING  CHANGES TO
          YOUR FORMS 10-Q FOR THE  QUARTERS  ENDED  MARCH 31,  2005 AND JUNE 30,
          2005.  SPECIFICALLY  THE  FOLLOWING  DISCREPANCIES  WERE NOTED IN YOUR
          CERTIFICATIONS:

          (A)  REFERENCE  SHOULD BE MADE TO RULE "15d-15(e)" OF THE EXCHANGE ACT
               RATHER THAN RULE "15d-14(e);"
          (B)  REFERENCE  TO "RULE  15d-15(f)"  OF THE  EXCHANGE ACT WAS OMITTED
               FROM THE CERTIFICATIONS FILED;
          (C)  ALL REFERENCES TO "COMPANY" SHOULD BE REPLACED WITH "REGISTRANT;"

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          (D)  ALL  REFERENCES  TO  "ANNUAL  REPORT"  SHOULD  BE  REPLACED  WITH
               "REPORT;"
          (E)  IN PARAGRAPH  4(d), THE PHRASE "FOURTH FISCAL  QUARTER" SHOULD BE
               REPLACED  WITH "MOST  RECENT  FISCAL  QUARTER  (THE  REGISTRANT'S
               FOURTH FISCAL QUARTER IN THE CASE OF AN ANNUAL REPORT)."

          We will file a Form  10-K/A for the fiscal  year  ended  December  31,
          2004,  and Form 10-Q/A for the quarters  ended March 31, 2005 and June
          30, 2005 and make conforming changes consistent with this comment.

     In connection with the foregoing responses to your comments, the Registrant
acknowledges:

     -    Company is responsible for the adequacy and accuracy of the disclosure
          in the filing;
     -    SEC staff  comments or changes to  disclosure in response to SEC staff
          comments do not  foreclose the SEC from taking any action with respect
          to the filing; and
     -    Company  may  not  assert  SEC  staff  comments  as a  defense  in any
          proceeding  initiated  by the  SEC or any  person  under  the  federal
          securities laws of the United States.

Sincerely,
Mission West Properties, Inc.
/s/ Carl E. Berg
Carl E. Berg
Chairman and CEO



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