<PAGE>


                      SECURITIES AND EXCHANGE COMMISSION
                            Washington, D.C. 20549

                                  FORM 10-QSB

(Mark One)

   X  QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE
      SECURITIES EXCHANGE ACT OF 1934

               For the quarterly period ended September 30, 1998
                                              ------------------
                                      OR

      TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
      EXCHANGE ACT OF 1934

           For the transition period from              to            
                                         --------------  ----------------

                        Commission file number 0-10272
                                              --------

           Winthrop Residential Associates I, A Limited Partnership
           --------------------------------------------------------
       (Exact name of small business issuer as specified in its charter)

               Maryland                                  04-2720493
----------------------------------------  --------------------------------------
    (State or other jurisdiction of         (I.R.S. Employer Identification No.)
     incorporation or organization)

 Five Cambridge Center, Cambridge, MA                    02142-1493
----------------------------------------  --------------------------------------
(Address of principal executive office)                  (Zip Code)

       Registrant's telephone number, including area code (617) 234-3000

Indicate by check mark whether Registrant (1) has filed all reports required
to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934
during the preceding 12 months (or for such shorter period that the Registrant
was required to file such reports), and (2) has been subject to such filing
requirements for the past 90 days. Yes  X    No
                                      ------   ------

                                    1 of 12

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           WINTHROP RESIDENTIAL ASSOCIATES I, A LIMITED PARTNERSHIP
           --------------------------------------------------------
                        FORM 10-QSB SEPTEMBER 30, 1998
                        ------------------------------

                        PART 1 - FINANCIAL INFORMATION
                        ------------------------------

Item 1. Financial Statements.

Balance Sheets (Unaudited)

(In Thousands, Except Unit Data)

<TABLE>
<CAPTION>

                                                                                 September 30,            December 31,
                                                                                     1998                     1997
                                                                              --------------------    ---------------------
<S>                                                                          <C>                      <C>                
Assets
------

Cash and cash equivalents                                                     $               467      $               251
Note receivable                                                                               105                       --
Investment in Local Limited Partnership                                                       333                      700
                                                                              --------------------    ---------------------

      Total Assets                                                            $               905     $                951
                                                                              ====================    =====================

Liabilities and Partners' Capital
---------------------------------

Liabilities:

Accrued interest and expenses                                                 $                41      $                22
Loan payable                                                                                  289                      289
                                                                              --------------------    ---------------------

      Total Liabilities                                                                       330                      311
                                                                              --------------------    ---------------------

Partners' Capital:

Limited Partners -

      Units of Limited Partnership Interest, 
      $1,000 stated value per unit; 25,676 
      units authorized; 25,595 units issued
      and outstanding                                                                       1,665                    1,728
General Partners deficit                                                                   (1,090)                  (1,088)
                                                                              --------------------    ---------------------

      Total Partners' Capital                                                                 575                      640
                                                                              --------------------    ---------------------

      Total Liabilities and Partners' Capital                                 $               905      $               951
                                                                              ====================    =====================
</TABLE>



                      See notes to financial statements.

                                    2 of 12

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           WINTHROP RESIDENTIAL ASSOCIATES I, A LIMITED PARTNERSHIP
           --------------------------------------------------------
                        FORM 10-QSB SEPTEMBER 30, 1998
                        ------------------------------

Statements of Income (Unaudited)

(In Thousands, Except Unit Data)

<TABLE>
<CAPTION>

                                                           For the Three Months Ended               For The Nine Months Ended
                                                        September 30,      September 30,        September 30,      September 30,
                                                            1998                1997                1998                1997
                                                       ----------------   -----------------    ----------------   -----------------
<S>                                                   <C>                <C>                   <C>               <C>             
Income:

     Income from Local Limited Partnership
       cash distributions                              $            --    $             24      $           74    $            104
     Equity in net loss of Local Limited
       Partnership                                                 (21)                (34)                (21)                (34)
     Interest                                                        8                   3                  12                  10
     Gain on sale of property from Local
       Limited Partnership                                          --                 500                  --                 500
     Loss on sale of  investment in
       Local Limited Partnership                                   (23)                 --                 (23)                 --
                                                       ----------------   -----------------    ----------------   -----------------

        Total (loss) income                                        (36)                493                  42                 580
                                                       ----------------   -----------------    ----------------   -----------------

Expenses:

     Amortization                                                   --                   1                  --                   5
     Interest                                                        8                  10                  21                  41
     General and administrative                                     27                  24                  81                  64
     Management fees                                                --                   2                   5                  10
                                                       ----------------   -----------------    ----------------   -----------------

        Total expenses                                              35                  37                 107                 120
                                                       ----------------   -----------------    ----------------   -----------------

Net (loss) income                                       $          (71)    $           456      $          (65)   $            460
                                                       ================   =================    ================   =================

Net (loss) income allocated to General Partners         $           (2)    $             3      $           (2)   $              3
                                                       ================   =================    ================   =================

Net (loss) income allocated to Limited Partners         $          (69)    $           453      $          (63)   $            457
                                                       ================   =================    ================   =================

Net (loss) income per Unit of Limited
   Partnership Interest                                $         (2.70)   $          17.70      $        (2.46)   $          17.86
                                                       ================   =================    ================   =================
</TABLE>



                      See notes to financial statements.

                                    3 of 12

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           WINTHROP RESIDENTIAL ASSOCIATES I, A LIMITED PARTNERSHIP
           --------------------------------------------------------

                        FORM 10-QSB SEPTEMBER 30, 1998
                        ------------------------------

Statements of Partners' Capital (Unaudited)

(In Thousands, Except Unit Data)

<TABLE>
<CAPTION>

                                                       Units of
                                                        Limited             General            Limited
                                                      Partnership          Partners'          Partners'           Total
                                                        Interest            Deficit            Capital           Capital
                                                    -----------------   -----------------  ----------------  ----------------


<S>                                                <C>                 <C>                <C>               <C>            
Balance - January 1, 1998                                     25,595    $         (1,088)  $         1,728   $           640

     Net loss                                                                         (2)              (63)              (65)
                                                    -----------------   -----------------  ----------------  ----------------

Balance - September 30, 1998                                  25,595    $         (1,090)  $         1,665   $           575
                                                    =================   =================  ================  ================
</TABLE>









                      See notes to financial statements.

                                    4 of 12


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           WINTHROP RESIDENTIAL ASSOCIATES I, A LIMITED PARTNERSHIP
           --------------------------------------------------------

                        FORM 10-QSB SEPTEMBER 30, 1998
                        ------------------------------

Statements of Cash Flows (Unaudited)

(In Thousands)
<TABLE>
<CAPTION>

                                                                                       For The Nine Months Ended
                                                                                 September 30,           September 30,
                                                                                     1998                     1997
                                                                              --------------------    ---------------------
<S>                                                                          <C>                     <C>                 
Cash Flows From Operating Activities:

Net (loss) income                                                             $               (65)    $                460
Adjustments to reconcile net (loss) income to net cash provided
  by (used in) operating activities:
      Amortization                                                                             --                        5
      Equity in net loss of Local Limited Partnership                                          21                       34
      Loss on sale of investment in Local Limited Partnership                                  23                       --
      Gain on sale of property from Local Limited Partnership                                  --                     (500)

Changes in assets and liabilities:
      Decrease in accounts payable and
         accrued expenses                                                                      (2)                      (9)
                                                                              --------------------    ---------------------

      Net cash used in operating activities                                                   (23)                     (10)
                                                                              --------------------    ---------------------

Cash Flows From Investing Activities:

      Expenses relating to sale of investment in Local
         Limited Partnership                                                                   (2)                      --
      Collections of note receivable                                                           70                       --
      Distributions received from Local Limited Partnership                                   150                       --
      Proceeds from Local Limited Partnership sale of property                                 --                      500
                                                                              --------------------    ---------------------

      Net cash provided by investing activities                                               218                      500
                                                                              --------------------    ---------------------

Cash Flows From Financing Activities:

      Repayment of loans payable to affiliate                                                  --                     (377)
      Increase (decrease) in accrued interest payable                                          21                     (154)
                                                                              --------------------    ---------------------

      Net cash provided by (used in) financing activities                                      21                     (531)
                                                                              --------------------    ---------------------

Net increase (decrease) in cash                                                               216                      (41)

Cash and cash equivalents, beginning of period                                                251                      280
                                                                              --------------------    ---------------------

Cash and cash equivalents, end of period                                      $               467     $                239
                                                                              ====================    =====================

Supplemental Disclosure of Cash Flow Information:

      Cash paid for interest                                                  $                --     $                195
                                                                              ====================    =====================

Sale of Investment in Local Limited Partnership - See Note 3
</TABLE>

                      See notes to financial statements.

                                    5 of 12


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           WINTHROP RESIDENTIAL ASSOCIATES I, A LIMITED PARTNERSHIP
           --------------------------------------------------------

                        FORM 10-QSB SEPTEMBER 30, 1998
                        ------------------------------

                         NOTES TO FINANCIAL STATEMENTS
                         -----------------------------

1.   General

     The accompanying financial statements, footnotes and discussions should
     be read in conjunction with the financial statements, related footnotes
     and discussions contained in the Partnership's annual report on Form
     10-KSB for the year ended December 31, 1997.

     The financial information contained herein is unaudited. In the opinion
     of management, all adjustments necessary for a fair presentation of such
     financial information have been included. All adjustments are of a normal
     recurring nature, except as discussed in Note 3. The balance sheet at
     December 31, 1997, was derived from audited financial statements at such
     date.

     The results of operations for the nine months ended September 30, 1998
     and 1997 are not necessarily indicative of the results to be expected for
     the full year.

2.   Related Party Transactions

     Management fees earned by an affiliate of the Managing General Partner
     totaled $10,000 for the nine months ended September 30, 1997. Commencing
     December 16, 1997, an unaffiliated third party began providing management
     services to the Partnership.

3.   Sale of Investment in Local Limited Partnership

     The Partnership sold a portion of its interest in a Local Limited
     Partnership, First Investment Limited Partnership 1 ("Copperfield
     Apartments"), to the general partner of the Local Limited Partnership.
     The Partnership now owns a 50% interest in Copperfield Apartments. The
     sales price was $175,000, payable with a promissory note, maturing on
     December 31, 2008, and secured by the interest in the Partnership. The
     promissory note accrues interest at 8% per annum. As specified in the
     promissory note, one half of the general partner's future distributions
     from Copperfield Apartments will be required to repay the note. During
     September 1998, the general partner of Copperfield Apartments repaid
     $70,000 of the principal balance and $5,000 of accrued interest. During
     1997, the Partnership recorded a $762,000 write-down of its investment in
     Copperfield Apartments to its net realizable value.

4.   Mortgage Refinancing

     On August 31, 1998, Copperfield Apartments refinanced its mortgage. The new
     mortgage in the amount of $1,200,000 replaced indebtedness of approximately
     $725,000. The mortgage bears interest at 6.40%, requires monthly payments
     of $8,000 and matures on September 1, 2008, with a balloon payment of
     approximately $1,039,000. A premium is to be calculated under the terms of
     the mortgage if the loan is prepaid. During September 1998, Copperfield
     Apartments distributed $150,000 of refinancing proceeds to the Partnership.

                                    6 of 12


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           WINTHROP RESIDENTIAL ASSOCIATES I, A LIMITED PARTNERSHIP
           --------------------------------------------------------

                        FORM 10-QSB SEPTEMBER 30, 1998
                        ------------------------------

Item 2.      Management's Discussion and Analysis or Plan of Operation
             ---------------------------------------------------------

             The matters discussed in this Form 10-QSB contain certain
             forward-looking statements and involve risks and uncertainties
             (including changing market conditions, competitive and regulatory
             matters, etc.) detailed in the disclosure contained in this Form
             10-QSB and the other filings with the Securities and Exchange
             Commission made by the Partnership from time to time. The
             discussion of the Partnership's liquidity, capital resources and
             results of operations, including forward-looking statements
             pertaining to such matters, does not take into account the
             effects of any changes to the Partnership's operations.
             Accordingly, actual results could differ materially from those
             projected in the forward-looking statements as a result of a
             number of factors, including those identified herein.

             This Item should be read in conjunction with the financial
             statements and other items contained elsewhere in the report.

             Liquidity and Capital Resources
             -------------------------------

             As of September 30, 1998, the Partnership retained an equity
             interest in six Local Limited Partnerships. During July 1997,
             Washington Square Limited Partnership sold the Heritage Hills
             Townhouses property. This Local Limited Partnership was 
             terminated in the fourth quarter of 1997.

             The level of liquidity based on cash and cash equivalents
             experienced an $216,000 increase for the nine months ended
             September 30, 1998, as compared to December 31, 1997. The
             Partnership's $218,000 of cash provided by investing activities
             and an increase in accrued interest payable of $21,000 (financing
             activities), were only partially offset by $23,000 of cash used
             in operating activities. Investing activities consisted of
             $150,000 of refinancing proceeds distributed by First Investment
             Limited Partnership I ("Copperfield Apartments"), one of the
             Local Limited Partnerships which the Partnership has an equity
             interest, and $70,000 of collections of a note receivable (see
             Item 1 Note 3), which were only partially offset by $2,000 of
             expenses relating to the sale of the investment in Copperfield
             Apartments. At September 30, 1998, the Partnership had $467,000
             in cash and cash equivalents, which has been invested primarily
             in short-term-certificates of deposit and money market accounts.

             The Partnership's primary source of income is distributions from
             the Local Limited Partnerships. The Partnership requires cash to
             pay management fees, general and administrative expenses and to
             make capital contributions to any of the Local Limited
             Partnerships which the Managing General Partner deems to be in
             the Partnership's best interest to preserve its ownership
             interest. To date, all cash requirements have been satisfied by
             interest income, cash distributed by the Local Limited
             Partnerships to the Partnership or by loans.

             On December 16, 1997, the Managing General Partner and certain of
             its affiliates entered into a Service Agreement with Coordinated
             Services of Valdosta, LLC ("Coordinated Services"), pursuant to
             which Coordinated Services was retained to provide asset
             management and investor services to the Partnership and certain
             affiliated partnerships. As a result of this agreement,
             Coordinated Services has the right to direct the day to day
             affairs of the Partnership, including without limitation,
             reviewing and analyzing potential sale, refinancing or
             restructuring proposals by Local Limited Partnerships,
             preparation of all Partnership reports, maintaining Partnership
             records and maintaining

                                    7 of 12


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           WINTHROP RESIDENTIAL ASSOCIATES I, A LIMITED PARTNERSHIP
           --------------------------------------------------------

                        FORM 10-QSB SEPTEMBER 30, 1998
                        ------------------------------

Item 2.      Management's Discussion and Analysis or Plan of Operation 
             ----------------------------------------------------------
             (Continued)
             -----------

             Liquidity and Capital Resources (Continued)
             -------------------------------------------

             bank accounts of the Partnership. Coordinated Services is not
             permitted, however, without the consent of the Managing General
             Partner, or as otherwise required under the terms of the
             Partnership's Agreement of Limited Partnership (the "Partnership
             Agreement") to, among other things, cause the Partnership to
             consent to a sale of an asset or cause the Partnership to file
             for bankruptcy. As compensation for providing these services, the
             Managing General Partner and its affiliates assigned to
             Coordinated Services all of their rights to receive fees from the
             Partnership, as provided in the Partnership Agreement.

             The loan payable to an affiliate of the Managing General Partner
             was assigned to an unaffiliated third party on October 27, 1997.
             The loan, which bears interest at prime plus 1%, is repayable
             from cash flows generated by the Local Limited Partnerships and
             the proceeds of any sales of real estate owned by the Local
             Limited Partnerships. The outstanding principal balance and
             accrued interest on the loan was approximately $321,000 at
             September 30, 1998. The Partnership did not make cash
             distributions to its partners during 1998 or 1997.

             The Partnership does not intend to make advances to fund future
             operating deficits incurred by any Local Limited Partnership, but
             retains its prerogative to exercise business judgment to reverse
             this position if circumstances change. Moreover, the Partnership
             is not obligated to provide any additional funds to the Local
             Limited Partnerships to fund operating deficits. If a Local
             Limited Partnership sustains continuing operating deficits and
             has no other sources of funding, it is likely that it will
             eventually default on its mortgage obligations and risk a
             foreclosure on its property by the lender. If a foreclosure were
             to occur, the Local Limited Partnership would lose its investment
             in the property and would incur a tax liability due to the
             recapture of tax benefits taken in prior years. The Partnership,
             as an owner of the Local Limited Partnership, would share these
             consequences in proportion to its ownership interest in the Local
             Limited Partnership.

             On September 1, 1996, the Local Limited Partnership which owns
             The Villas Apartments signed a provisional workout agreement,
             expiring August 31, 1997, with the U.S. Department of Housing and
             Urban Development ("HUD"). The provisional workout agreement has
             been extended until December 30, 1998. The general partner of the
             Local Limited Partnership is currently negotiating with HUD to
             reach a resolution. There can be no assurance that a resolution
             of this default will be reached with HUD. If the general partner
             of the Local Limited Partnership and HUD are unable to agree on a
             resolution, the Property could be lost through foreclosure. The
             Partnership's investment in this Local Limited Partnership had
             previously been written-down to zero.

             The Cedar Lake Ltd. Local Limited Partnership, which owns Albany
             Landings Apartments, has incurred significant operating losses
             and cash flow deficits. If operations at the property do not
             improve, this property may be lost through foreclosure. The
             Partnership's investment in this Local Limited Partnership had
             previously been written-down to zero.

             The Partnership sold a portion of its interest in a Local Limited
             Partnership, First Investment Limited Partnership 1 ("Copperfield
             Apartments"), to the general partner of the Local Limited
             Partnership. The Partnership now owns a 50% interest in
             Copperfield Apartments. The sales price was $175,000, payable
             with a promissory note, maturing on December 31, 2008, and
             secured by

                                    8 of 12


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           WINTHROP RESIDENTIAL ASSOCIATES I, A LIMITED PARTNERSHIP
           --------------------------------------------------------

                        FORM 10-QSB SEPTEMBER 30, 1998
                        ------------------------------

Item 2.      Management's Discussion and Analysis or Plan of Operation 
             ----------------------------------------------------------
             (Continued)
             -----------

             Liquidity and Capital Resources (Continued)
             -------------------------------------------

             the interest in the Partnership. The promissory note accrues
             interest at 8% per annum. As specified in the promissory note,
             one half of the general partner's future distributions from
             Copperfield Apartments will be required to repay the note. During
             September 1998, the general partner of Copperfield Apartments
             repaid $70,000 of the principal balance and $5,000 of accrued
             interest.

             On August 31, 1998, Copperfield Apartments refinanced its
             mortgage. The new mortgage in the amount of $1,200,000 replaced
             indebtedness of approximately $725,000. The mortgage bears
             interest at 6.40%, requires monthly payments of $8,000 and
             matures on September 1, 2008, with a balloon payment of
             approximately $1,039,000. A premium is to be calculated under the
             terms of the mortgage if the loan is prepaid. During September
             1998, Copperfield Apartments distributed $150,000 of refinancing
             proceeds to the Partnership.

             The Partnership is dependent upon Coordinated Services and the
             management agents of the Local Limited Partnerships for
             management and administrative services. Coordinated Services has
             completed an assessment and believes that their computer systems
             will function properly with respect to dates in the Year 2000 and
             thereafter (the "Year 2000 Issue"). The management agents of the
             Local Limited Partnerships are at various stages of completing an
             assessment of their computer systems. These Year 2000 costs, if
             any, are the responsibility of the individual management agents.
             The Partnership does not expect that it will incur any material
             costs associated with, or be materially affected by, the Year
             2000 Issue.

             Results of Operations
             ---------------------

             Net income declined by $525,000 for the nine months ended
             September 30, 1998, as compared to 1997, due to a decrease in
             income of $538,000, which was only partially offset by a decrease
             in expenses of $13,000.

             Income declined primarily due to the $500,000 gain on sale of
             property from the Local Partnership owning the Heritage Hills
             Townhouses in 1997 as compared to the $23,000 loss on the sale of
             a portion of the Partnership's interest in Copperfield Apartments
             during 1998. During the nine months ended September 30, 1998, the
             Partnership received $51,000 from the Local Limited Partnership
             which owns the Lynwood property and $23,000 from the Shadowbrook
             property. The Shadowbrook property was lost through foreclosure
             during 1996, and accordingly no additional distributions are
             expected to be received. At September 30, 1997, $80,000 was
             received from the Local Limited Partnership which owns the
             Lynwood property and $24,000 from the Local Limited Partnerships
             owning the Heritage Hills Townhouses.

             Expenses declined primarily due to decreases in interest expense
             of $20,000 and management fees of $5,000, which were only
             partially offset by an increase in general and administrative
             expenses of $17,000. Interest expense declined due to a
             significant portion of the loan being repaid during the third
             quarter of 1997. General and administrative expenses increased
             due to the timing of certain expenses.

                                    9 of 12


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           WINTHROP RESIDENTIAL ASSOCIATES I, A LIMITED PARTNERSHIP
           --------------------------------------------------------

                        FORM 10-QSB SEPTEMBER 30, 1998
                        ------------------------------

Part II - Other Information

Item 6.    Exhibits and Reports on Form 8-K.
           ---------------------------------

           (a)    Exhibit 27

                  27.      Financial Data Schedule

                  99.      Supplementary Information Required Pursuant to 
                           Section 9.4 of the Partnership Agreement.

           (b)    Reports on Form 8-K:

                  No reports on Form 8-K were filed during the three months
ended September 30, 1998.

                                   10 of 12


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           WINTHROP RESIDENTIAL ASSOCIATES I, A LIMITED PARTNERSHIP
           --------------------------------------------------------

                        FORM 10-QSB SEPTEMBER 30, 1998
                        ------------------------------

                                  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, thereunto duly authorized.

                                   WINTHROP RESIDENTIAL ASSOCIATES I,
                                   ----------------------------------
                                   A LIMITED PARTNERSHIP
                                   ---------------------

                                   BY:    ONE WINTHROP PROPERTIES, INC.
                                          Managing General Partner

                                          BY:    /s/ Michael L. Ashner
                                                 -----------------------
                                                 Michael L. Ashner
                                                 Chief Executive Officer

                                          BY:    /s/ Edward V. Williams
                                                 -----------------------
                                                 Edward V. Williams
                                                 Chief Financial Officer

                                                 Dated: November 12, 1998

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