<PAGE>

                       SECURITIES AND EXCHANGE COMMISSION
                              Washington, DC 20549
                                   FORM 10-QSB
                   QUARTERLY REPORT UNDER SECTION 13 OR 15(d)
                     OF THE SECURITIES EXCHANGE ACT OF 1934

For the quarter ended September 30, 1999          Commission File Number 0-12210

                  PRESIDENTIAL ASSOCIATES I LIMITED PARTNERSHIP
                  ---------------------------------------------
        (exact name of small business issuer as specified in its charter)

               Maryland                                  04-2801764
------------------------------------        ------------------------------------
  (State or other jurisdiction of           (I.R.S. Employer Identification No.)
   incorporation or organization)

Five Cambridge Center, Cambridge, MA                        02142
------------------------------------              -------------------------
(Address of principle executive offices)                  (Zip Code)

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

Indicate by check mark whether the 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 / /
<PAGE>

PRESIDENTIAL ASSOCIATES I LIMITED PARTNERSHIP

PART 1 - FINANCIAL INFORMATION
ITEM 1. - FINANCIAL STATEMENTS
BALANCE SHEETS

--------------------------------------------------------------------------------
                                                          September     December
                                                           30, 1999     31, 1998
                                                         (Unaudited)   (Audited)
--------------------------------------------------------------------------------

                                     ASSETS

Assets
  Cash and cash equivalents                                $239,757     $186,610
  Due from Operating Partnership                                -        173,404
                                                           --------     --------

Total assets                                               $239,757     $360,014
                                                           ========     ========

                        LIABILITIES AND PARTNERS' CAPITAL

Liabilities and partners' capital
  Partners' capital                                        $239,757     $360,014
                                                           --------     --------


Total liabilities and partners' capital                    $239,757     $360,014
                                                           ========     ========


                       See notes to financial statements


                                      -2-
<PAGE>

PRESIDENTIAL ASSOCIATES I LIMITED PARTNERSHIP

STATEMENT OF OPERATIONS
(UNAUDITED)

                                      For the Three Months  For the Nine Months
                                       Ended September 30,   Ended September 30,
                                        1999       1998        1999      1998
                                       -------   ---------   --------  --------

INCOME
  Interest                             $ 2,094   $   2,034   $  7,255  $  5,710
  Distribution from operating
    partnership                            -           -      200,036   161,706
                                       -------   ---------   --------  --------

                                         2,094       2,034    207,291   167,416
                                       -------   ---------   --------  --------

EXPENSES
  Other expenses                         6,231      14,212      6,365    14,212
                                       -------   ---------   --------  --------
  Total operating expenses               6,231      14,212      6,365    14,212
                                       -------   ---------   --------  --------

Net income (loss)                      $(4,137)  $ (12,178)  $200,926  $153,204
                                       =======   =========   ========  ========

Net income per unit of limited
  partnership interest outstanding     $    (7)  $     (20)  $    337  $    257
                                       =======   =========   ========  ========

  (590 units issued and outstanding)

                       See notes to financial statements


                                      -3-
<PAGE>

PRESIDENTIAL ASSOCIATES I LIMITED PARTNERSHIP

STATEMENT OF CHANGES IN PARTNERS' CAPITAL

--------------------------------------------------------------------------------

                                             Linnaeus-
                                              Phoenix
For the Nine Months Ended        Winthrop   Associates    Investor      Total
September 30, 1999 and 1998      Financial    Limited     Limited     Partners'
(Unaudited)                      Co., Inc.  Partnership   Partners     Capital
--------------------------------------------------------------------------------

Balance, December 31, 1998       (270,262)   (572,171)    1,202,447     360,014

Net income                          1,005       1,005       198,916     200,926


Distributions                      (1,625)     (1,625)     (321,750)   (325,000)

Contributions                         -           -           3,817       3,817
                                ---------   ---------   -----------   ---------

Balance, September 30, 1999     $(270,882)  $(572,791)  $ 1,083,430   $ 239,757
                                =========   =========   ===========   =========

Balance, December 31, 1997      $(270,579)  $(572,488)  $ 1,136,507   $ 293,440

Net income                            766         766       151,672     153,204

Distributions                      (1,250)     (1,250)     (247,500)   (250,000)

Contributions                         -           -           2,935       2,935
                                ---------   ---------   -----------   ---------

Balance, September 30, 1998     $(271,063)  $(572,972)  $ 1,043,614   $ 199,579
                                =========   =========   ===========   =========

                       See notes to financial statements


                                      -4-
<PAGE>

PRESIDENTIAL ASSOCIATES I LIMITED PARTNERSHIP

STATEMENTS OF CASH FLOWS

--------------------------------------------------------------------------------
For the Nine Months Ended
September 30, 1999 and 1998 (Unaudited)                      1999       1998
--------------------------------------------------------------------------------

Cash flow from operating activities:
  Net income                                              $ 200,926   $ 153,204
  Adjustments to reconcile net income to
    net cash provided by operating activities
      Decrease in due from operating partnership            173,404      36,502
                                                          ---------   ---------

Net cash provided by operating activities                   374,330     189,706
                                                          ---------   ---------
Cash flows from financing activities:
  Partner distributions                                    (325,000)   (250,000)
  Contributions                                               3,817       2,935
                                                          ---------   ---------

Net cash used in financing activities                      (321,183)   (247,065)
                                                          ---------   ---------

Net increase (decrease) in cash and cash equivalents         53,147     (57,359)

Cash and cash equivalents at beginning of period            186,610     249,420
                                                          ---------   ---------

Cash and cash equivalents at end of period                $ 239,757   $ 192,061
                                                          =========   =========

                       See notes to financial statements


                                      -5-
<PAGE>

PRESIDENTIAL ASSOCIATES I LIMITED PARTNERSHIP

NOTES TO FINANCIAL STATEMENTS
September 30, 1999
(Unaudited)

1.    ACCOUNTING AND FINANCIAL REPORTING POLICIES

The condensed financial statements included herein have been prepared by the
Partnership, without audit, pursuant to the rules and regulations of the
Securities and Exchange Commission. The Partnership's accounting and financial
reporting policies are in conformity with generally accepted accounting
principles and include all adjustments in interim periods considered necessary
for a fair presentation of the results of operations. Certain information and
footnote disclosures normally included in financial statements prepared in
accordance with generally accepted accounting principles have been condensed or
omitted pursuant to such rules and regulations. It is suggested that these
condensed financial statements be read in conjunction with the financial
statements and the notes thereto included in the Partnership's Annual Report on
Form 10-KSB for the year ended December 31, 1998.

The accompanying financial statements reflect the Partnership's results of
operations for an interim period and are not necessarily indicative of the
results of operations for the year ending December 31, 1999.

2.    INVESTMENT IN OPERATING PARTNERSHIP

The Partnership accounts for its investment in Presidential Towers, Ltd. (the
"Operating Partnership") using the equity method of accounting. Under the equity
method of accounting, the initial investment is recorded at cost, increased or
decreased by the Partnership's share of income or losses, and decreased by
distributions. Equity in the loss of the Operating Partnership is no longer
recognized once the investment balance reaches zero.

The loss from the Operating Partnership, not recognized since the investment
balance reached zero, will be offset against the Partnership's share of future
income from the Operating Partnership.


                                      -6-
<PAGE>

PRESIDENTIAL ASSOCIATES I LIMITED PARTNERSHIP

ITEM 2 - MANAGEMENT'S DISCUSSION AND ANALYSIS OR PLAN OF OPERATION

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

Liquidity and Capital Resources

The Partnership's primary source of liquidity is distributions from Presidential
Towers Ltd., an Illinois limited partnership (the "Operating Partnership"). The
Partnership is responsible for paying various administrative costs associated
with monitoring the Partnership's investment in the Operating Partnership, and
paying various professional fees associated with the affairs of the Partnership.

During the nine months ended September 30, 1999 and September 30, 1998, the
Operating Partnership made distributions to the Partnership of $200,036 and
$161,706, respectively. In addition, the Partnership is entitled to receive an
annual distribution from the Operating Partnership as a reimbursement of the
Partnership's administrative expenses and professional fees up to an annual
maximum of $30,000.

The Partnership's liquidity based on cash and cash equivalents increased to
$239,757 at September 30, 1999 as compared to $186,610 at December 31, 1998. As
discussed above, the Partnership received a distribution from the Operating
Partnership; however, in July 1999 the Partnership made a distribution of
$325,000 to its partners. Future distributions to limited partners are
contingent upon the receipt by the Partnership of distributions from the
Operating Partnership.

Results of Operations

Operating results increased by $47,722 for the nine months ended September 30,
1999 as compared to the nine months ended September 30, 1998 due primarily to an
increase in distributions from the Operating Partnership in 1999. During the
quarter ended June 30, 1999, the partnership reached its maximum annual
operating partnership expense reimbursement of $30,000 and, accordingly,
incurred $6,231 of expenses during the quarter ended September 30, 1999.


                                      -7-
<PAGE>

PRESIDENTIAL ASSOCIATES I LIMITED PARTNERSHIP

PART II - OTHER INFORMATION

Item 6. Exhibit and reports on Form 8-K

        a)  Exhibits

            Exhibit 27, Financial Data Schedule B filed as an Exhibit to this
            report

        b)  Reports on Form 8-K

            No report on Form 8-K was required to be filed during the period


                                      -8-
<PAGE>

PRESIDENTIAL ASSOCIATES I LIMITED PARTNERSHIP

                                   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.

                                           PRESIDENTIAL ASSOCIATES I
                                           LIMITED PARTNERSHIP
                                           (Partnership)


                                           By:  Winthrop Financial Co., Inc.
                                                One of its General Partners


Date: November 4, 1999                     By:  /s/ Thomas C. Staples
                                                --------------------------------

                                                Thomas C. Staples
                                                Chief Financial Officer

Date: November 4, 1999                     By:  /s/ Michael L. Ashner
                                               ---------------------------------

                                               Michael L. Ashner
                                               Chief Executive Officer


                                      -9-