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 (Date of earliest event reported):
                        August 10, 2001 (August 9, 2001)



                         SENIOR HOUSING PROPERTIES TRUST
               (Exact name of registrant as specified in charter)




          Maryland                   001-15319                  04-3445278
(State or other jurisdiction        (Commission              (I.R.S. employer
     of incorporation)              file number)          identification number)




 400 Centre Street, Newton, Massachusetts                            02458
 (Address of principal executive offices)                          (Zip code)




         Registrant's telephone number, including area code:617-796-8350




Item 5.  Other Events.

         On  August  9,  2001  Senior  Housing  Properties  Trust  ("SNH" or the
"Company")  announced  that it has  entered  an  agreement  to acquire 31 senior
housing  communities from Crestline Capital  Corporation for approximately  $600
million.  The 31 communities contain 7,487 living units. The communities are all
managed by Marriott International,  Inc. ("Marriott") under long-term agreements
that extend through 2027 with renewal options  thereafter.  SNH will identify or
create a tenant  entity for the  communities  in order to  maintain  REIT status
under applicable IRS rules.

         A majority of the living  units in these  communities  are  independent
living apartments,  although many of the properties also have an assisted living
component and some special care or skilled  nursing beds.  Current  occupancy at
these  properties  is  approximately  91%; and about 90% of the gross  operating
revenues at these properties are paid by residents from private resources rather
than Medicare or Medicaid.

         Some of the properties being acquired are subject to approximately $235
million of existing  debt,  which may be assumed by SNH as part of the  purchase
price.  Crestline will issue approximately $150 million of new debt prior to the
closing,  which may be assumed  by SNH.  SNH also has the option to obtain up to
$25 million of unsecured  seller  financing for two years at an interest rate of
10% per annum. The remainder of the acquisition price may be initially funded by
drawings under SNH's available bank credit  facility.  The Company will consider
various alternatives for longer term financing before and after the closing.

         The 31 communities are located in 13 states, as follows:

        State                 Number of Properties            Number of Units
        -----                 --------------------            ---------------
Arizona                                 3                          913
California                              2                          405
Delaware                                5                          869
Florida                                 6                        1,423
Indiana                                 1                          221
Kansas                                  1                          207
Kentucky                                3                          606
Massachusetts                           1                          125
New Jersey                              1                          416
New Mexico                              1                          208




        State                 Number of Properties            Number of Units
        -----                 --------------------            ---------------
Ohio                                    1                          315
South Carolina                          1                          164
Texas                                   5                        1,615


Total:  13 states                 31 properties                  7,487/units


         The  transaction  is  subject  to the  conditions  described  below  in
addition to closing conditions  customary in real estate  transactions.  Because
the properties to be acquired by SNH represent a substantial part of Crestline's
assets, a Crestline shareholders' vote will be required.  Similarly, third party
approvals from Marriott under the management agreements and from certain lenders
will be  required.  Also,  as is common  in all  transactions  affecting  senior
housing and healthcare  facilities,  licensing and  regulatory  approvals in the
states  where the  properties  are located may be  required.  At this time,  SNH
expects that this transaction will close in early 2002.

         THIS CURRENT REPORT  CONTAINS  FORWARD  LOOKING  STATEMENTS  WITHIN THE
MEANING OF THE PRIVATE  SECURITIES  REFORM ACT OF 1995.  THESE  FORWARD  LOOKING
STATEMENTS  INCLUDE  REFERENCES  TO THE  POSSIBILITY  THAT  EXISTING DEBT MAY BE
ASSUMED, REFERENCES TO THE POSSIBLE AVAILABILITY OF NEW FINANCING, REFERENCES TO
SNH'S  ABILITY TO LOCATE OR CREATE A TENANT IN  COMPLIANCE  WITH IRS REIT RULES,
AND REFERENCES OR IMPLICATIONS  THAT REQUIRED  APPROVALS,  CONSENTS AND LICENSES
WILL BE OBTAINED.  THESE FORWARD LOOKING STATEMENTS ARE BASED UPON SNH'S CURRENT
BELIEFS AND  EXPECTATIONS,  BUT THEY ARE NOT  GUARANTEED TO OCCUR.  FOR EXAMPLE,
FINANCING FOR THIS ACQUISITION MAY NOT BE AVAILABLE; SNH MAY BE UNABLE TO LOCATE
OR CREATE A TENANT IN COMPLIANCE  WITH IRS RULES;  SNH MAY BE UNABLE TO REMAIN A
REIT;  SNH  MAY BE  UNABLE  TO PAY  EXISTING  OR  INCREASED  DIVIDENDS;  AND THE
APPROVALS  AND  CONSENTS  REQUIRED  TO  CONCLUDE  THIS  TRANSACTION  MAY  NOT BE
OBTAINED.  SOME OF THESE FORWARD  LOOKING  STATEMENTS  MAY NOT OCCUR FOR REASONS
WHICH WE CONTROL  AND SOME MAY NOT OCCUR FOR  REASONS  BEYOND OUR  CONTROL.  FOR
EXAMPLE,  WE MAY REFUSE TO MAKE  ACCOMMODATIONS  NECESSARY TO OBTAIN THIRD PARTY
APPROVALS,  OR CHANGES IN CAPITAL  MARKETS WHICH ARE BEYOND OUR CONTROL MAY MAKE
REASONABLE   FINANCING  FOR  THIS  TRANSACTION   IMPOSSIBLE.   INVESTORS  SHOULD
UNDERSTAND THAT THIS TRANSACTION MAY NOT OCCUR. INVESTORS SHOULD NOT PLACE UNDUE
RELIANCE UPON FORWARD LOOKING STATEMENTS.


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                                   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.

                              SENIOR HOUSING PROPERTIES TRUST


                              By: /s/ David J. Hegarty
                                 Name:  David J. Hegarty
                                 Title: President, Chief Operating Officer
                                         and Chief Financial Officer



Date:  August 10, 2001



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