PROSPECTUS SUPPLEMENT

The following  information  supplements the attached  prospectus of Mission West
Properties, Inc. dated November 27, 1998.

On December 28, 1998, the Company's shareholders approved or ratified all of the
following transactions:

     o    A private  placement of 6,495,058 shares of the Company's Common Stock
          for $4.50 per share to a group of accredited investors.

     o    Ratification  of the Company's  becoming the sole general  partner and
          acquiring  approximately 12.11% of the total partnership  interests in
          the Operating Partnerships and to approve other related matters.

     o    Approval of the  issuance of up to  93,398,705  shares of Common Stock
          issuable  upon the  redemption  or  exchange  of  93,398,705  units of
          limited  partnership  interests  held by or  issuable  to the  limited
          partners in the four limited partnerships,  including 33,919,072 units
          issuable upon the acquisition of certain pending development  projects
          from Mr. Berg and certain of his affiliates.

     o    Approval  of the  acquisition  by the Company of the right to acquire,
          through the  Operating  Partnership,  certain  commercial  R&D pending
          building   developments   consisting  of  approximately  1.02  million
          rentable square feet from Mr. Berg and certain of his affiliates,  and
          the  acquisition of an option with respect to future  developments  on
          land currently held by Mr. Berg and certain of his affiliates.

     o    Approval of the  reincorporation  of the Company under the laws of the
          State of Maryland through a merger with Mission West Properties, Inc.,
          a Maryland corporation,  a newly formed wholly owned subsidiary of the
          Company.

The Company has completed the sale of 6,495,058  shares of Common Stock,  no par
value,  to  accredited  investors  and  has  received  total  cash  proceeds  of
approximately  $28,328,000.  All of the proceeds of the sale of the Common Stock
have been used to repay  principal  owed by the Company  under four demand notes
payable to the Operating Partnerships.

On December 29, 1998 the Company entered into the following agreements:

     o    Exchange Rights Agreement with all of the existing limited partners in
          the Operating Partnerships.

     o    Pending  Projects  Acquisition  Agreement with Mr. Berg and certain of
          his affiliates.

     o    Berg Land Holdings  Option  Agreement with Mr. Berg and certain of his
          affiliates.

Also, on December 30, 1998, the Company merged into its wholly owned subsidiary,
Mission West Properties,  Inc., and thereby reincorporated under the laws of the
State  of  Maryland.   Existing  stock   certificates   held  by  the  Company's
stockholders  will  continue  to  represent  shares of Common  Stock,  par value
$0.001,  of the new corporation  and  stockholders do not need to submit them in
exchange.

Separately,  the Company's  management has determined with its tax advisors that
neither the Company nor its stockholders will derive  significant  benefits from
an election to become a real estate  investment  trust  ("REIT") for federal and
state income tax purposes with respect to the Company's tax year ended  December
31, 1998. Instead, the Company will elect REIT status for its 1999 tax year.

Additionally,  the  Company's  board of directors has decided not to declare any
dividends on the Company's Common Stock with respect to the year ending December
31, 1998.

The Company's  current  outside  directors are John Bolger,  Lawrence Helzel and
William  Hasler.  Mr.  Bolger  is a private  investor  and  former  CFO of Cisco
Systems.  Mr.  Helzel,  a private  investor,  is a member of the  Pacific  Stock
Exchange and serves as a director  for Pacific  Gateway  Properties,  a publicly
traded real estate  company.  Mr.  Hasler is a former Dean of the Haas School of
Business,  University of California,  Berkeley and is currently Co-CEO of Aphton
Corporation, a publicly trades bio-pharmaceutical company.

The Board of Directors has established an Audit Committee, whose current members
are John Bolger and William  Hasler,  a  Compensation  Committee  whose  current
members  are John  Bolger and  Lawrence  Helzel,  and an  Independent  Directors
Committee,  who current  members are John  Bolger,  Lawrence  Helzel and William
Hasler.

Bradley  Perkins,  Vice  President  and  General  Counsel,  will resign from the
Company effective January 8, 1999 to return to the  semiconductor  industry.  At
this time, the Company does not plan to replace Mr. Perkins.

Mission West Properties intends to operate as a self-managed,  self-administered
and  fully  integrated  REIT  engaged  in the  management,  leasing,  marketing,
development and acquisition of commercial R & D properties, primarily located in
the Silicon Valley portion of the San Francisco Bay Area. Currently, the Company
manages 71 properties totaling approximately 4.51 million square feet.