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


September 15, 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
    Filed March 16, 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
contained in your letter dated August 31, 2005. The Staff comment is repeated in
capitalized  letters  below,  and the  Company's  response  appears  immediately
beneath each comment.

FORM 10-K FOR THE YEAR ENDED DECEMBER 31, 2004

ITEM 7. MANAGEMENTS  DISCUSSION AND ANALYSIS OF FINANCIAL  CONDITION AND RESULTS
OF OPERATIONS - FUNDS FROM OPERATIONS, PAGE 44

1.   WE NOTE THAT YOU USE FFO AS A MEASURE  OF  PERFORMANCE.  YOU ALSO  INDICATE
     THAT,  "ALONG  WITH  CASH  FLOWS  FROM  OPERATING   ACTIVITIES,   FINANCING
     ACTIVITIES  AND  INVESTING  ACTIVITIES,   IT  PROVIDES  INVESTORS  WITH  AN
     UNDERSTANDING  OF OUR  ABILITY TO INCUR AND SERVICE  DEBT AND MAKE  CAPITAL
     EXPENDITURES"  WHICH SUGGESTS THAT YOU ALSO USE FFO AS A LIQUIDITY MEASURE.
     PLEASE  TELL US AND IN FUTURE  FILINGS  REVISE YOUR  DISCLOSURE  TO CLARIFY
     WHETHER YOU USE FFO AS A MEASURE OF OPERATING  PERFORMANCE OR LIQUIDITY AND
     EXPLAIN WHY YOU BELIEVE FFO IS A USEFUL INDICATOR OF OPERATING  PERFORMANCE
     OR  LIQUIDITY.  FURTHER,  IF YOU CONSIDER FFO TO BE A MEASURE OF LIQUIDITY,
     PLEASE  ALSO  REVISE  YOUR  RECONCILIATION  OF FFO TO THE  MOST  COMPARABLE
     FINANCIAL MEASURE PRESENTED IN ACCORDANCE WITH GAAP. REFER TO ITEM 10(e)(i)
     OF REGULATION S-K.

     We believe the REIT industry has  established  FFO as a standard of measure
     of operating  performance for the REIT industry and acknowledge that FFO is



     not a GAAP  measure of  financial  performance.  In future  filings we will
     delete the sentence,  "Management  considers FFO an appropriate  measure of
     performance of an equity REIT because, along with cash flows from operating
     activities,  financing  activities  and investing  activities,  it provides
     investors  with an  understanding  of our ability to incur and service debt
     and make capital expenditures."

     Because we intend to cease  describing  FFO as a measure  of the  Company's
     liquidity,   we  do  not  believe  it  will  be   necessary  to  provide  a
     reconciliation of FFO to a related GAAP measure of liquidity.

ITEM 7A. QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK, PAGE 48

2.   YOUR  DISCLOSURE  HERE  AND IN  NOTE 2 ON PAGE  61 IS NOT  CONSISTENT  WITH
     RESPECT  TO THE FAIR VALUE OF YOUR FIXED  RATE  DEBT.  PLEASE  REVISE  YOUR
     DISCLOSURE IN FUTURE FILINGS TO CORRECTLY  DISCLOSE THE FAIR VALUE OF FIXED
     RATE DEBT AND UPDATE YOUR RELATED DISCUSSION, AS NECESSARY.

     We will revise our  disclosure in future filings to disclose the fair value
     of fixed rate debt  consistently in Item 7A.  Quantitative  and Qualitative
     Disclosures  About  Market  Risk and Note 2 to the  Consolidated  Financial
     Statements.

NOTE 2. SUMMARY OF  SIGNIFICANT  ACCOUNTING  POLICIES - IMPAIRMENT OF LONG-LIVED
ASSETS, PAGE 57

3.   WE NOTE FROM YOUR  DISCLOSURE ON PAGE 16 THAT YOU HAVE NUMEROUS  PROPERTIES
     WITH AVERAGE 2004  OCCUPANCIES OF 0%, 0% OCCUPANCY AS OF DECEMBER 31, 2004,
     OR BOTH. WE ALSO NOTE THAT YOU RECOGNIZED AN IMPAIRMENT LOSS RELATED TO THE
     ONE  ASSET  HELD FOR SALE AT  DECEMBER  31,  2004.  PLEASE  TELL US HOW YOU
     DETERMINED  THE FAIR VALUE OF THE REMAINING  PROPERTIES  WITH MINIMAL OR NO
     OCCUPANCY AT DECEMBER 31, 2004 WHEN  MEASURING  ANY  IMPAIRMENT  LOSS UNDER
     SFAS 144.  PLEASE ALSO TELL US WHETHER ANY OF THESE  PROPERTIES ARE SUBJECT
     TO THE  RESTRICTION  DISCLOSED  ON  PAGE 11 AND HOW  THIS  RESTRICTION  WAS
     CONSIDERED  IN  DETERMINING  THE  FAIR  VALUE  OF SUCH  PROPERTY.  REFER TO
     PARAGRAPHS 22-24 OF SFAS 144.

     The analysis that we prepare in connection with determining if there may be
     any  asset  impairment  loss  under  SFAS 144  considers  several  factors,
     including  the specific  guidance in of SFAS 144.  Properties  selected for
     evaluation  included those that were vacant as of December 31, 2004 as well
     as  properties  scheduled  to become  vacant  during 2005.  The  individual
     properties  are  tested  for  impairment  based  upon a  comparison  of the
     carrying value to the sum of the undiscounted cash flows expected to result
     from a disposition of the property.  For purposes of the undiscounted  cash
     flow  calculation,  the  Company  assumed an  overall 10 year hold  period,
     consisting

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     of up to a 36 month  period to lease the  vacant  space,  which  represents
     management's  estimate  of the  time to lease  vacant  space  under  market
     conditions  as of December 31, 2004,  and an 84 month leased  period.  Cash
     inflows during the leased period are based upon estimated  market rents for
     comparable  leases of like kind space within the various  submarkets in the
     Silicon  Valley of the San Francisco Bay Area. The  assumptions  include 3%
     annual  increases  in the rent  during  the  projected  leased  term.  Cash
     outflows  during the lease up period  are based  upon the costs  associated
     with the vacant  portion of the building  which  includes  property  taxes,
     landscaping  and  insurance  (the "Common  Area Cost or CAC").  The CAC are
     generally 100% recovered from the tenant during the leased period under the
     terms of the Company's  triple net ("NNN") leases,  and therefore,  the CAC
     and other  related  reimbursement  income are  excluded  from the cash flow
     calculation  during the leased period.  Cash outflows  relating to deferred
     maintenance have  historically  been minimal (but have been considered on a
     property by property  basis) due to  provisions  in the Company's NNN lease
     agreements  that require a tenant to maintain the property  during the term
     of the lease in "Good  Condition and Repair" which  minimizes the amount of
     deferred maintenance and repair costs incurred by the Company to re-lease a
     property.  The cash inflows relating to the gross terminal value at the end
     of the leased period are based on the average net  operating  income of the
     property  during  the  hold  period,  divided  by  the  appropriate  market
     capitalization  rate  (ranging from 8% to 9% as of December 31, 2004) based
     on comparable  sales data for like kind buildings in the market.  The gross
     terminal  value was  reduced  by  estimated  selling  costs of 5%.  The net
     terminal  value  (gross  terminal  value  less 5%  selling  costs) was then
     evaluated  for overall  reasonableness  by comparing it to relevant  market
     sales data.

     Based on the factors outlined above,  our analysis  determined that the sum
     of the undiscounted cash flows expected to result from the use and eventual
     disposition  of each  respective  vacant  property was in excess of its net
     book value as of December 31, 2004.

     There is a requirement set forth in the limited  partnership  agreement for
     each  Operating   Partnership  that  owns  certain  properties   originally
     contributed  by Carl E. Berg,  Clyde J. Berg or John  Kontrabecki  that the
     Company obtain  consent  before  selling one of the properties  that one or
     more of them had contributed to the Company because all of these properties
     have  substantial  unrealized  tax  gain  that  would  be  taxable  to  the
     contributing  limited  partner(s).  This  requirement  has not  impeded the
     Company's operations to date because the Company invests in commercial real
     estate for rental value and for long term holding  periods.  The  Company's
     objective is to pay  substantial  dividends from operations and to increase
     the value of its outstanding equity interests,  not to sell properties at a
     gain and  distribute  the proceeds to  shareholders.  Where the Company has
     identified  opportunities  to sell a particular  property,  the Company has
     been able to complete a tax

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     deferred  exchange in accordance with Section 1031 of the Internal  Revenue
     Code in order to roll the existing  investment into a new income  producing
     property. Therefore, we have not discounted the value of a property subject
     to this  restriction in determining the fair value of our properties  under
     SFAS 144.

ITEM 9A. REPORT OF MANAGEMENT ON INTERNAL CONTROL OVER FINANCIAL REPORTING, PAGE
85

4.   IN FUTURE  FILINGS,  PLEASE  DISCLOSE  THE  CONCLUSIONS  OF YOUR  PRINCIPAL
     EXECUTIVE AND PRINCIPAL  FINANCIAL  OFFICERS REGARDING THE EFFECTIVENESS OF
     YOUR DISCLOSURE CONTROLS AND PROCEDURES AS OF THE END OF THE PERIOD COVERED
     BY THE REPORT. REFER TO ITEM 307 OF REGULATION S-K.

     We will comply with this comment in future filings.

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

5.   PLEASE REVISE YOUR CERTIFICATIONS  FILED AS EXHIBITS 31.1, 31.2 AND 31.3 TO
     REFLECT THE LANGUAGE  EXACTLY AS SET FORTH IN ITEM 601(b)(31) OF REGULATION
     S-K.

     The wording for the matters  required to be certified  under Rule 13a-14(a)
     as set  forth  in the  referenced  exhibits  is  exactly  the  same as Item
     601(b)(31).  We  acknowledge  that these 10-K exhibits do use "the Company"
     instead of "registrant"  to identify the Company,  do refer to this "Annual
     Report" rather than any report generally,  and do unintentionally  omit the
     parenthetical  reference to Rule  15d-15(f),  (which  definition is, in any
     event,  identical to the cited Rule 13a-15(f)).  We respectfully propose to
     eliminate  these  immaterial  discrepancies  in future  filings  in lieu of
     filing amended exhibits.

     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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