<PAGE>   1
       As filed with the Securities and Exchange Commission on May 15,1997

                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                    FORM 10-Q

 [x] QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE
     ACT OF 1934
                    For quarterly period ended March 31, 1997

 [ ] 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: 0-21443

                        PLYMOUTH COMMERCIAL MORTGAGE FUND
             (Exact name of registrant as specified in its charter)

              Delaware                                74-6439983
   (State or other jurisdiction or        (I.R.S. Employer Identification No.)
   incorporation or organization)

                          c/o Greystone Advisers, Inc.,
                          13333 Blanco Road, Suite 314,
                          San Antonio, Texas 78216-7756
          (Address of principal executive offices, including zip code)

                                  210-493-3971
              (Registrant's telephone number, including area code)

                                 Not Applicable
              (Former name, former address, and former fiscal year,
                         if changed since last report)

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.

                                 [X] Yes [ ] No


As of May 15, 1997, 921,627 of the registrant's common shares of beneficial
interest, no par value, were outstanding.
<PAGE>   2

PART I - FINANCIAL INFORMATION


                       PLYMOUTH COMMERCIAL MORTGAGE FUND
                      Statement of Assets and Liabilities
                      March 31, 1997 and December 31, 1996
                                  (unaudited)


<TABLE>
<CAPTION>

                    Assets                    March 31, 1997   December 31, 1996
                    ------                    --------------   -----------------
<S>                                           <C>              <C>
Investments in securities at value, cost
  of $2,189,090 and $3,810,445                  $4,150,790       $2,763,554
Investments in affiliates                          130,566          130,566
Cash                                               247,802        5,082,109
Repurchase Agreement                             4,215,852          502,351
Accounts Receivable                                 28,210            6,451
Organizational Costs                                96,200          104,000
Other Assets                                         5,901          103,641
                                                ----------       ----------
Total Assets                                    $8,875,321       $8,692,672
                                                ----------       ----------

                  Liabilities
                  -----------
Accounts Payable                                $  233,658       $   66,822
Declared and Unpaid Dividends                       74,213
Investment Advisory Fee Payable                          -           16,677
Escrow Funds                                        19,016           16,927
                                                ----------       ----------
Total Liabilities                               $  326,886       $  100,426

                  Net Assets
                  ---------- 
Common shares of beneficial interest, 
  no par value, 1,750,000 shares authorized,
  921,627 shares issued and outstanding          7,976,773        7,976,773 
Accumulated undistributed income                  (220,091)        (168,039) 
Accumulated undistributed net realized gains       375,290          132,930 
Accumulated undistributed equity in 
  earnings of subsidiary                            76,118           76,118
Accumulated undistributed unrealized gain 
  on investments                                   340,345          574,464 
                                                ----------       ---------- 
Total Net Assets ($9.28 and $9.32 per share)     8,548,434        8,592,246

Total Liabilities & Net Assets                  $8,875,321       $8,692,672
                                                ----------       ----------
</TABLE>




The accompanying notes are an integral part of these financial statements.


                                       1

<PAGE>   3
                       PLYMOUTH COMMERCIAL MORTGAGE FUND
                            Statement of Operations
                  for the 3 month period ended March 31, 1997
                                  (unaudited)

Income:
Investment Income:
  Interest                                                            $  46,758
  Other Investment Income                                                72,887
                                                                      ---------
Total Investment Income                                                 119,645

Expenses:
  Operating Expenses                                                    112,391
  Management Fees                                                        59,306
                                                                      ---------
Total Expenses                                                          171,697

Net Investment Income                                                 $ (52,052)

Gain on investments                                                     316,573
Change in unrealized gain (loss) on investments                        (234,119)
Earnings in equity of affiliate                                              --
                                                                      ---------
Net increase (decrease) in net assets resulting from operations       $  30,402
                                                                      =========


   The accompanying notes are an integral part of these financial statements.

                                       2
<PAGE>   4

                       PLYMOUTH COMMERCIAL MORTGAGE FUND
                       Statement of Changes in Net Assets
                  for the 3 month period ended March 31, 1997
                                  (unaudited)


<TABLE>

<S>                                                     <C>
Operations before distributions:
  Net Investment Income                                  $ (52,052)
  Net realized gain on investments                         316,573
  Change in unrealized gain (loss) on investments         (234,119)
                                                         ---------
Increase in net assets from operations before
  distributions                                          $  30,402

Distributions from:
  Undistributed net investment income                    $       -
  Undistributed net realized gain on investments           (74,213)
  Unrealized appreciation of investments                         -
                                                         ---------
(Decrease) in net assets from distributions              $ (74,213)

Capital share transactions                                       -
                                                         ---------
Total Increase in net assets                             $ (43,811)
                                                         ---------
Net assets, beginning of period                          $       -
Net assets, end of period                                $ (43,811)

Per Share Data
  Investment income                                      $    0.13
  Expenses                                                    0.19
  Net realized gain on investments                            0.34
Change in unrealized gain (loss) on investments              (0.25)
                                                         ---------
Increase in net assets from operations
  before distributions                                        0.03

Distributions from realized gains on securities               0.08
                                                         ---------
Net increase (decrease) in net asset value                   (0.05)

Net asset value:
Inception                                                     9.32
End of period                                            $    9.28
                                                         ---------

Ratios:
Ratio of expenses to average net assets (%)                   2.00%
Ratio of net investment income to average assets (%)         -0.61%

</TABLE>




The accompanying notes are an integral part of these financial statements.


                                       3

<PAGE>   5
                       PLYMOUTH COMMERCIAL MORTGAGE FUND
                             Statement of Cashflows
                  for the 3 month period ended March 31, 1997
                                  (unaudited)

<TABLE>
<S>                                                                 <C>
Cash flows from operating activities:
Increase in net assets from operations before distributions         $    30,402

Adjustments to reconcile increase in net assets from operations 
before distributions to net cash provided by operating activities:
  Depreciation and amortization                                           7,800
  (Increase) decrease in unrealized gain                                234,119
  (Increase) decrease in repurchase agreement                        (3,713,501)
  (Increase) decrease in investments in affiliates                           --
  (Increase) decrease in accounts receivable                            (21,759)
  (Increase) decrease in other assets                                    97,740
  Decrease (increase) in current liabilities                            226,460
  Deferred income taxes                                                      --
                                                                    -----------
Net cash provided by operating activities                            (3,138,739)

Cash flows from investing activities:
  Purchases of securities                                            (1,621,355)
                                                                    -----------
Net cash used by investing activities                                (1,621,355)

Net increase (decrease) in cash and cash equivalents                $(4,760,094)
                                                                    ===========

Cash and cash equivalents at beginning of period                    $ 5,082,109
Cash and cash equivalents at end of period                          $   322,015
</TABLE>



   The accompanying notes are an integral part of these financial statements.


                                       4
<PAGE>   6
1. ORGANIZATION AND BUSINESS PURPOSE

         Plymouth Commercial Mortgage Fund, a Delaware business trust, (the
"Fund") was organized on August 23, 1996 and commenced operations on September
27, 1996. The Fund seeks to achieve a high level of current income by purchasing
loans where the obligor is having trouble meeting the loan's contractual
requirements. The loans that the Fund purchases are typically secured by
commercial real estate.

         The Fund has elected to be regulated as a business development company
under the Investment Company Act of 1940, as amended ("1940 Act").


2.  SIGNIFICANT ACCOUNTING POLICIES

     A.  Basis of Presentation- The financial statements included herein have
         been prepared in accordance with generally accepted accounting
         principles for interim financial information and the instructions to
         Form 10-Q and Article 6 of Regulation S-X. Certain information and
         footnotes normally included in financial statements prepared in
         accordance with generally accepted accounting principles have been
         condensed or omitted. The Fund believes that the information that is
         presented is a fair representation and reflects all which are necessary
         for a fair presentation of the results of operations for the interim
         periods.

     B.  Security Valuation -There is no publicly quoted market for the Fund's
         impaired loan portfolio. As such, the fair value of the portfolio is
         established by the Fund's Board of Trustees using their best judgment.
         Such values are based upon what the Board believes the Fund could
         reasonably expect to receive for each impaired loan in an orderly
         disposition over a reasonable time period.

         In establishing the fair value of a loan, the Board considers aspects
         about the individual loan as well as the general economy. Such factors
         include but are not limited to: the type of loan, whether the borrower
         is currently meeting the contractual terms of the obligation, the
         length of time that the borrower has or has not been meeting the
         contractual terms, the probability that the borrower will begin or stop
         making payments, the value of the collateral and the guarantees
         securing the loans, the Fund's historical experience selling the type
         of loan being valued, various standard financial measurements, the
         remaining contract terms, and prevailing interest rates.

         Certain elements of the valuation procedure involve subjective
         judgment. Because the majority of the Fund's impaired loans are
         delinquent, no assurance can be given that the Fund will be able to
         recover the fair value that the Board has established. The Fund's
         impaired loans are not typically backed by any government guarantee or
         private credit enhancement. In many cases, the Fund will also incur
         certain costs and delays in attempting to assert its right to payment
         or in foreclosing on the loan's collateral. The actual value realized
         on any particular loan will vary from the values determined by the
         Board and can only be determined in negotiations between the Fund and
         third parties.

         In asserting its rights, the Fund will often attempt to foreclose on a
         loan and acquire the collateral. Pursuant to the terms of its credit
         agreement, any real estate that is acquired through foreclosure is held
         by Plymouth REO, a wholly owned subsidiary of the Fund. Real estate
         acquired through foreclosure is recorded at its estimated fair value.

     C.  Federal Income Taxes - The Fund intends to elect the special income tax
         treatment available to "regulated investment companies" under
         Subchapter M of the Internal Revenue Code. If the Fund qualifies as a
         regulated investment company and distributes to shareholders annually
         in a timely manner at least 90% of its "investment company taxable
         income," as defined by the Code


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<PAGE>   7
         (i.e., net investment income, including accrued discount, and net
         short-term capital gains), it will not be subject to federal income tax
         on the portion of its taxable investment income and net capital gain
         distributed to shareholders as required under the Code. In addition, if
         the Fund distributes in a timely manner 98% of its net capital gain
         income for each one-year period, and distributes 98% of its investment
         company taxable income for each calendar year (as well as any income
         not distributed in prior years), it will not be subject to the 4%
         nondeductible federal excise tax imposed with respect to certain
         undistributed income of regulated investment companies.

     D.  Distributions to Shareholders - Dividends to shareholders are recorded
         on the payment date. The Fund declared a dividend of $74,213 for the
         quarter ended March 31, 1997 payable on or before May 31, 1997 to
         shareholders of record on March 31, 1997.

     E.  Other - Principal and interest payments due on notes held by the Fund
         are recognized on the date received. Interest income is typically not
         accrued because of the impaired nature of the Fund's loan portfolio.


3.  INVESTMENT ADVISORY AGREEMENT

     The Fund has to entered into an Investment Advisory Agreement (the
"Agreement") with Emerald Advisers, Inc., a Delaware corporation, a registered
investment adviser, (the "Adviser"), under the Investment Advisers Act of 1940
(the "Adviser's Act"), as amended. (As of October 28, 1996, the Adviser changed
its name from Emerald Advisers, Inc. to Greystone Advisers, Inc. No change in
the Adviser's operations was made in conjunction with the name change.) Unless
terminated as described, the Agreement remains in effect until September 22,
1998. Thereafter it will need to be specifically approved at least annually by
the Board of Trustees, including a majority of its members casting their votes
in person who are not "interested persons" of the Fund (as defined by the 1940
Act) at a meeting called for the purpose of voting on such approval or by "vote
of a majority of the outstanding voting securities" of the Fund. The Agreement
can be terminated by the Fund at any time, without payment of any penalty, on
sixty day's written notice to the Adviser if the decision to terminate has been
made by the Board of Trustees or by "vote of a majority of the outstanding
voting securities" of the Fund. The Agreement will terminate automatically in
the event of its assignment.

     Under the Agreement, the Adviser will manage the investments of the Fund,
subject to the supervision and control of the Fund's Board of Trustees.
Specifically, the Adviser will identify, evaluate, structure, close and monitor
the investments made by the Fund.

     The Adviser will be required to pay all expenses incurred by it in
rendering its services. Generally, these expenses include the cost of office
space, telephone service, equipment and personnel required to perform its
obligations under the Agreement. The Fund will be required to pay its operating
expenses and reimburse the Adviser promptly for expenses which the Adviser may
pay on the Fund's behalf, except those specifically required to be borne by the
Adviser under the Agreement. Without limitation, such expenses will include: all
expenses of any offering and sale by the Fund of its shares; the fees and
disbursements of the Fund's counsel, accountants, and custodian; fees and
expenses incurred in producing and effecting filings with federal and state
securities administrators; costs of the Fund's periodic reports to and other
communications with the Fund's shareholders; fees and expenses of members of the
Fund's Board of Trustees who are not directors, officers or employees of the
Adviser; premiums for the fidelity bond maintained by the Fund; all costs
related to portfolio investments, including without limitation financing costs,
legal and accounting fees, expenses related to protecting or maintaining the
value of the loan portfolio or its underlying collateral, and other professional
or technical fees and expenses (e.g., credit reports, title searches and
delivery charges, property taxes, insurance premiums, long-distance telephone
charges, costs of specialized consultants such as accountants or
industry-specific technical experts, and travel expenses) incurred in acquiring,
monitoring, negotiating, working-out, and effecting


                                       6
<PAGE>   8
disposition of such investments, as well as responding to any litigation arising
therefrom; and all expenses related to any borrowings by the Fund.

         During the term of this Agreement, the Fund will pay to the Adviser, on
the 15th day of each month: (a) a fee calculated at an effective annual rate of
5.94% of the Fund's invested assets as of the end of the previous month; and (b)
a fee calculated at an effective annual rate of 0.48% of the Fund's cash and
short-term investments as of the end of the previous month. For purposes of
calculating the fee to be paid on a monthly basis, "invested assets" means the
asset value as determined by the Board as of the end of the previous fiscal
quarter minus cash, short-term investments, intangible assets, and the amount of
collections applied to the carrying value of the loan portfolio since the end of
the previous quarter, plus the cost of loans purchased and capitalized advances
to protect portfolio investments or underlying collateral since the end of the
previous quarter.


4.       INVESTMENTS

         The Fund invests primarily in impaired loans of companies that qualify
as "eligible portfolio companies" as defined in Section 2(a)(46) of the 1940 Act
or in securities that otherwise qualify for investment as permitted in Section
55(a)(1) through (6). These loans are carried on the Statement of Assets and
Liabilities as of September 31, 1996, at fair value, as determined in good faith
by the Fund's Board of Trustees.

         These loans typically are offered at auction in packages of multiple
loans. Sellers include entities such as the Federal Deposit Insurance
Corporation ("FDIC"), banks, savings and loans, insurance companies and other
financial institutions. The Fund's investments in loan packages will be directed
by the Adviser. The Fund holds its real estate assets in a wholly-owned
subsidiary as required in the agreement establishing its senior credit facility.

          Generally, a loan is considered impaired when, based on current
information and events, it is probable that a creditor will be unable to collect
all amounts due according to the contractual terms of the loan agreement unless
the borrower receives material assistance. While several types of impaired loans
are available for purchase, the Fund's portfolio will be concentrated in
impaired loans secured by commercial real estate. For both financial and
regulatory reasons, commercial banks, either directly or indirectly through the
FDIC, make these loans available for sale in packages with prices that are
typically more than $1 million per package. Quite often the sale of impaired
loans in this market offers creditors the only alternative to foreclosure.


5.       INDEBTEDNESS

         As of March 31, 1997, the Fund had no indebtedness. The Fund has open
an $8,000,000 line of credit with a Texas bank.


ITEM 2: MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS
OF OPERATIONS.

(1)      Material Changes in Financial Condition

         Net assets during the period declined slightly and will continue to
decline for the next few quarters as the loans that were acquired from SWF 1995
Limited Partnership ("SWF 1995") are resolved. This is not a long term trend.
The decline is triggered by the realization of a gain over the carrying cost for
federal income tax purposes. When the loans were acquired from SWF 1995, the
value that was established for the transaction was more than this carrying cost.
However, because the loans were acquired in a tax-free


                                       7
<PAGE>   9
exchange, the carrying cast was not adjusted. Instead an unrealized gain was
recorded on the Fund's books for the difference between the carrying cost of the
loans and their fair value. As the unrealized gain is realized, the Fund is
distributing it to shareholders. The distributions have lead to a short term
decline in the Fund's net asset value.

         There is a difference of approximately $375,000 ($.41 per share)
between the unrealized gain attributed to the remaining assets acquired from SWF
1995 and their carrying basis for federal income tax purposes. There is also
approximately $234,000 ($.25 per share) in already realized gain that will have
to be distributed by the end of January 1998, further reducing net asset value.

         This decline is similar to stock and bond mutual funds. Such a decline
will not occur with new loans that the Fund purchases.

(2)      Material Changes in the Results of Operations

         The three month period ended March 31, 1997 represents the first period
in which the Fund was fully operating. We have been very pleased with the
quantity and quality of loans that have been available and the price that we
have been able to receive for the assets that we have disposed of.

         During the period, we submitted total bids of $19,451,000 and were the
successful bidder on two packages with a total cost of $2,076,000 . One loan
purchase was particularly important to us because we purchased it directly from
a Texas bank instead of through a sealed bid auction. Because we had the luxury
of being able to review a complete loan file, ask questions, and talk to the
obligor before buying the loan, we felt much more confident about our bid. As a
result, the bank also got a better offer from us than they would have had we
been asked to review the loan as part of an auction. To us, this was an ideal
situation for both parties and we are eagerly pursuing other "private deals."

         We were very pleased with the amount of loans that we were able to
either settle or sell during the quarter, particularly since the loan portfolio
consists primarily of the harder to work assets remaining in the limited
partnership that was acquired in September 1996. The Fund received a total of
$1,022,088 during the quarter. Most of these collections came from six loans
that we either settled or sold for a total of $927,039. Our overall return on
the initial cost of the loan plus all expenses was a very significant 26% annual
internal rate of return although we did settle one loan for loss of $20,032. The
most significant gain was $119,439 on one loan which we had purchased as part of
a package of loans but had assigned no cost.


PART II - OTHER INFORMATION

1.       LEGAL PROCEEDINGS
         None.

2.       CHANGES IN SECURITIES
         (b)  None.
         (c)  None.

3.       DEFAULTS UPON SENIOR SECURITIES
         (c)  None.
         (d)  None.

1.       SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS
         None.

                                       8
<PAGE>   10
2.    OTHER INFORMATION
      None.

           6.   EXHIBITS AND REPORTS ON FORM 8-K
           (a)  EXHIBITS-

                (2) Plan of acquisition, reorganization, arrangement, 
                    liquidation or succession: (None)

                (3)(i) (A)Certificate of Trust of the registrant, as filed 
                       August 23, 1996(1)
                       (B)Declaration of Trust of the registrant, dated August
                       23, 1996(1)

                (3)(ii)Bylaws of the registrant, dated September 3, 1996(1)

                (4)    (A)Loan Agreement between Comerica Bank-Texas and the
                       registrant, dated September 27, 1996(2)
                       (B)Agreement to furnish to the Commission upon request
                       a copy of Subordinated Note Agreement between the 
                       registrant and SouthWest Holding Company, Inc., dated 
                       September 27, 1996(2)

                (10)   (A)Investment Advisory Agreement by and between the 
                       registrant and Emerald Advisers, Inc. (former name of 
                       Greystone Advisers, Inc.), dated September 22, 1996(2)
                       (B)Custodial Agreement by and between Comerica Bank-
                       Texas and the registrant, dated September 27, 1996(2)

                (15)   Letter re unaudited interim financial information: (None)

                (18)   Letter re change in accounting principles: (None)

                (19)   Report furnished to security holders: (None)

                (22)   Published report regarding matters submitted to vote of
                       security holders: (None)

                (23)   Consents of experts and counsel: (None)

                (24)   Power of attorney: (None)

                (27)   Financial Data Schedule (3)*

           (b)  REPORTS ON FORM 8-K- None.



------------------
(1) Incorporated herein by reference from the registrant's initial registration
statement on Form 10 (File No. 0-21443), as filed with the Commission on
September 27, 1996.

(2) Incorporated herein by reference from amendment #1 of the registrant's 
initial registration statement on Form 10 (File No. 0-21443), as filed with the
Commission on January 15, 1997.

(3) Filed herewith.


                                       9
<PAGE>   11
                                   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.


                                   PLYMOUTH COMMERCIAL MORTGAGE FUND

May 15, 1997                         /s/ Robert R. Swendson
                                   ---------------------------------------------
                                   Robert R. Swendson, President and
                                   Chief Executive Officer


May 15, 1997                         /s/ John C. Mosher
                                   ---------------------------------------------
                                   John C. Mosher, Vice President and
                                   Chief Financial Officer (Principal
                                   Financial Officer)


                                       10