<PAGE>   1


                     U.S. SECURITIES AND EXCHANGE COMMISSION
                              Washington, DC 20549

                                   ----------

                                  FORM 10-QSB/A

                                   ----------


[X]      QUARTERLY REPORT UNDER SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE
         ACT OF 1934 FOR THE QUARTERLY PERIOD ENDED September 30, 2000.


[ ]      TRANSITION REPORT UNDER SECTION 13 OR 15(d) OF THE SECURITIES
         EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM ______________ TO
         ______________.



                         Commission file number 1-11900



                       INTEGRATED SECURITY SYSTEMS, INC.
       -----------------------------------------------------------------
       (Exact name of small business issuer as specified in its charter)



<TABLE>
<S>                                                                        <C>
                           DELAWARE                                                     75-2422983
(State or other jurisdiction of incorporation or organization)             (I.R.S. Employer Identification No.)


          8200 SPRINGWOOD DRIVE, SUITE 230, IRVING, TEXAS                                    75063
             (Address of principal executive offices)                                     (Zip Code)
</TABLE>



                                 (972) 444-8280
                           (Issuer's telephone number)



Check whether the issuer (1) filed all reports required to be filed by Section
13 or 15(d) of the Exchange Act during the past 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 [ ]

As of January 8, 2001, 10,782,417 shares of the Registrant's common stock were
outstanding.

Transitional Small Business Disclosure Format: Yes  [ ]  No  [X]



                                  Page 1 of 12
<PAGE>   2


                        INTEGRATED SECURITY SYSTEMS, INC.
                                      INDEX

<TABLE>
<CAPTION>
                                                                                             Page
                                                                                             ----
<S>                                                                                          <C>
PART I.  FINANCIAL INFORMATION

         Item 1.  Financial Statements

                  Consolidated Balance Sheets at September 30, 2000 (unaudited)
                           and June 30, 2000                                                   3

                  Consolidated Statements of Operations (unaudited) for the three
                           months ended September 30, 2000 and 1999                            4

                  Consolidated Statements of Cash Flows (unaudited) for the three
                           months ended September 30, 2000 and 1999                            5

                  Notes to Financial Statements                                                6

         Item 2.  Management's Discussion and Analysis or Plan of Operation                    8

PART II.  OTHER INFORMATION

         Item 1. Legal Proceedings                                                            11

         Item 2. Changes in Securities                                                        11

         Item 3. Defaults Upon Senior Securities                                              11

         Item 4. Submission of Matters to a Vote of Security Holders                          11

         Item 5. Other Information                                                            11

         Item 6. Exhibits and Reports on Form 8-K                                             11

SIGNATURES                                                                                    12
</TABLE>



                                  Page 2 of 12
<PAGE>   3


                                           PART I. FINANCIAL INFORMATION

Item 1.  Financial Statements.

                        INTEGRATED SECURITY SYSTEMS, INC.
                           Consolidated Balance Sheets

<TABLE>
<CAPTION>
                                                                                   September 30,          June 30,
                                                                                       2000                 2000
                                                                                   -------------        ------------
                                                                                    (Unaudited)
<S>                                                                                 <C>                 <C>
                                ASSETS
Current assets:
   Cash and cash equivalents                                                        $    103,195        $     99,636
   Accounts receivable, net of allowance for doubtful
     accounts of $64,847 and $58,847, respectively                                     1,002,626           1,201,491
   Inventories                                                                           596,725             585,486
   Notes receivable                                                                       28,546              28,546
   Unbilled receivables                                                                  180,079             252,567
   Other current assets                                                                  113,347             112,718
                                                                                    ------------        ------------
     Total current assets                                                              2,024,518           2,280,444

Property and equipment, net                                                              893,736             921,695
Capitalized software development costs, net                                               56,856             113,713
Other assets                                                                              21,418              16,898
                                                                                    ------------        ------------
     Total assets                                                                   $  2,996,528        $  3,332,750
                                                                                    ============        ============

                LIABILITIES AND STOCKHOLDERS' DEFICIT
Current liabilities:
   Accounts payable                                                                 $    957,324        $    582,717
   Accrued liabilities                                                                   383,967             440,072
   Current portion of long-term debt                                                   6,643,925           6,135,260
                                                                                    ------------        ------------
     Total current liabilities                                                      $  7,985,216        $  7,158,049
                                                                                    ------------        ------------

Long-term debt                                                                           705,554             728,331

Stockholders' deficit:
   Preferred stock, $.01 par value, 750,000 shares authorized;
     102,250 shares issued and outstanding (liquidation value
     of $2,045,000)                                                                        1,023               1,023
   Common stock, $.01 par value, 35,000,000 shares
     authorized; 10,572,545 and 10,564,145 shares,
     respectively, issued; and 10,522,545 and 10,514,145
     shares, respectively, outstanding                                                   105,725             105,641
   Additional paid in capital                                                         14,502,963          14,502,963
   Accumulated deficit                                                               (20,185,203)        (19,044,507)
   Treasury stock, 50,000 shares                                                        (118,750)           (118,750)
                                                                                    ------------        ------------
     Total stockholders' deficit                                                      (5,694,242)         (4,553,630)
                                                                                    ------------        ------------
       Total liabilities and stockholders' deficit                                  $  2,996,528        $  3,332,750
                                                                                    ============        ============
</TABLE>


               The accompanying notes are an integral part of the
                       consolidated financial statements.



                                  Page 3 of 12
<PAGE>   4


                        INTEGRATED SECURITY SYSTEMS, INC.
                      Consolidated Statements of Operations
                                   (Unaudited)


<TABLE>
<CAPTION>
                                                   For the Three Months Ended
                                                         September 30,
                                                --------------------------------
                                                    2000                1999
                                                ------------        ------------
<S>                                             <C>                 <C>
Sales                                           $  1,223,507        $  1,902,141
Cost of sales                                        921,108           1,175,094
                                                ------------        ------------
Gross margin                                         302,399             727,047
                                                ------------        ------------

Operating expenses:
  Selling, general and administrative              1,083,385           1,147,968
  Research and product development                   145,475              91,663
                                                ------------        ------------
                                                   1,228,860           1,239,631
                                                ------------        ------------

Loss from operations                                (926,461)           (512,584)

Other income (expense):
  Interest income                                        139              10,167
  Interest expense                                  (172,292)           (148,750)
                                                ------------        ------------

Net loss                                          (1,098,614)           (651,167)

Preferred dividends                                  (42,081)                 --
                                                ------------        ------------

Net loss allocable to common stockholders       $ (1,140,695)       $   (651,167)
                                                ============        ============

Weighted average common and
   common equivalent shares
   outstanding  - basic and diluted               10,518,345          10,491,773
                                                ============        ============

Net loss per share                              $      (0.11)       $      (0.06)
                                                ============        ============
</TABLE>

               The accompanying notes are an integral part of the
                       consolidated financial statements.



                                  Page 4 of 12
<PAGE>   5


                        INTEGRATED SECURITY SYSTEMS, INC.
                      Consolidated Statements of Cash Flows
                                   (Unaudited)


<TABLE>
<CAPTION>
                                                             For the Three Months Ended
                                                                    September 30,
                                                           -------------------------------
                                                               2000               1999
                                                           ------------       ------------
<S>                                                        <C>                <C>
Cash flows from operating activities:
   Net loss                                                $(1,098,614)       $  (651,168)
   Adjustments to reconcile net loss to net cash
     used by operating activities:
     Depreciation                                               42,001             59,372
     Amortization                                               56,857             56,857
     Provision for bad debt                                      6,000              5,400
     Provision for warranty reserve                             16,500             12,000
     Provision for inventory reserve                           (14,239)                --
     Deferred revenue                                           72,488             (9,542)
     Expenses paid with common stock                                --             19,773
     Changes in operating assets and liabilities:
       Accounts receivable                                     192,866           (196,786)
       Inventories                                               3,000             43,246
       Notes receivable                                             --            (66,000)
       Other assets                                             (5,150)           (30,601)
       Accounts payable                                        374,605            127,517
       Accrued liabilities                                     (72,607)           (82,380)
                                                           -----------        -----------
           Net cash used in operating activities              (426,293)          (712,312)
                                                           -----------        -----------

Cash flows from investing activities:
   Purchase of property and equipment                          (14,042)           (17,436)
                                                           -----------        -----------
           Net cash used in investing activities               (14,042)           (17,436)
                                                           -----------        -----------

Cash flows from financing activities:
   Issuance of preferred stock                                      --            250,000
   Issuance of common stock                                         84                 --
   Dividends on preferred stock                                (42,080)                --
   Payments on debt and other liabilities                      (51,945)           (12,636)
   Proceeds from notes payable and long-term debt              537,835            390,763
                                                           -----------        -----------
           Net cash provided by financing activities           443,894            628,127
                                                           -----------        -----------

Increase (decrease) in cash and cash equivalents                 3,559           (101,621)
Cash and cash equivalents at beginning of period                99,636            251,113
                                                           -----------        -----------
Cash and cash equivalents at end of period                 $   103,195        $   149,492
                                                           ===========        ===========
</TABLE>

               The accompanying notes are an integral part of the
                       consolidated financial statements.



                                  Page 5 of 12
<PAGE>   6


                        INTEGRATED SECURITY SYSTEMS, INC.
             Notes to Consolidated Financial Statements (Unaudited)
                   Quarters Ended September 30, 2000 and 1999

NOTE 1 - BASIS OF PRESENTATION

The accompanying unaudited consolidated financial statements have been prepared
in accordance with generally accepted accounting principles for interim
financial information. Accordingly, they do not include all of the information
and footnotes required by generally accepted accounting principles for complete
financial statements. In the opinion of management, all adjustments (all of
which are normal recurring accruals) considered necessary for a fair
presentation have been included. Operating results for the interim period are
not necessarily indicative of the results that may be expected for the fiscal
year ending June 30, 2001.

The accompanying financial statements include the accounts of Integrated
Security Systems, Inc. and all of its subsidiaries, with all significant
intercompany accounts and transactions eliminated. For further information,
refer to the consolidated financial statements and footnotes thereto included in
the Company's fiscal 2000 Annual Report on Form 10-KSB filed on October 13,
2000, and all amendments to the Form 10-KSB filed after October 13, 2000 with
the Securities and Exchange Commission.

NOTE 2 - RECLASSIFICATION

Certain reclassification of prior year amounts have been made to conform to the
current period presentation.

NOTE 3 - SUBSEQUENT EVENT - FINANCING

In November 2000, the Company entered into an agreement for a financial
restructuring plan with its two largest stockholders, Renaissance Capital Growth
& Income Fund III, Inc. and Renaissance US Growth and Income Trust PLC. Both of
these Renaissance entities are managed by Renaissance Capital Group, Inc. The
financial restructuring plan provides that the Renaissance entities will
exchange all their outstanding convertible debentures, convertible notes, notes,
and accrued interest into a new class of the Company's preferred stock.

The new class of the Company's preferred stock, Series G preferred stock, would
have approximately $6 million principal amount, a 5% dividend that accrues but
is not paid until redemption, and would be convertible into shares of the
Company's common stock at $.20 per share. The Series G preferred stock would be
redeemable in years three through five, or earlier from the proceeds of the sale
of certain assets.

As part of the financial restructuring plan, Renaissance Capital Growth & Income
Fund III, Inc. and Renaissance US Growth and Income Trust PLC have agreed to
advance a combined $1 million in promissory notes to the Company in a private
placement. In the event the Company receives at least $100,000 in additional
subscriptions under this placement, the $1 million in promissory notes will be
exchangeable into the Company's Series F preferred stock. The Series F preferred
stock will have a 5% dividend, which accrues for two years, and is convertible
into common shares at $.20 per share. The promissory notes will mature 120 days
after the date of the promissory notes unless exchanged for the shares of the
Series F preferred stock.

The financial restructuring plan is subject to stockholder approval at the 2000
annual meeting of the stockholders. The Company currently does not have a
sufficient number of shares of Common Stock authorized to accommodate these
transactions. The Company will seek stockholder approval to amend its
certificate of incorporation to increase the number of authorized shares of
Common Stock.



                                  Page 6 of 12
<PAGE>   7


NOTE 4 - BUSINESS SEGMENTS

Information for the Company's reportable segments for the three months ended
September 30, 2000 and 1999 is as follows:

<TABLE>
<CAPTION>
                                      For the Three Months Ended
                                            September 30,
                                    ------------------------------
                                       2000                1999
                                    -----------        -----------
<S>                                 <C>                <C>
Sales
   B&B Electromatic, Inc.           $ 1,098,004        $ 1,508,998
   Intelli-Site, Inc.                   125,503            393,143
                                    -----------        -----------
                                    $ 1,223,507        $ 1,902,141
                                    ===========        ===========

Income (loss) from operations
   B&B Electromatic, Inc.           $   (40,610)       $   182,608
   Intelli-Site, Inc.                  (593,536)          (353,590)
   Corporate                           (292,315)          (341,602)
                                    -----------        -----------
                                    $  (926,461)       $  (512,584)
                                    ===========        ===========
</TABLE>




                                  Page 7 of 12
<PAGE>   8


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

FORWARD LOOKING STATEMENTS

This quarterly report on Form 10-QSB includes "forward-looking statements"
within the meaning of Section 27A of the Securities Act of 1933, as amended, and
Section 21E of the Securities Exchange Act of 1934, as amended. Forward-looking
statements can be identified by the use of forward-looking terminology such as
"may," "believe," "expect," "intend," "plan," "seek," "anticipate," "estimate,"
or "continue" or the negative of those words or other variations or comparable
terminology.

All statements other than statements of historical fact included in this
quarterly report on Form 10-QSB, including the statements under "Part I.--Item
2. Management's Discussion and Analysis or Plan of Operation" and located
elsewhere in this quarterly report on Form 10-QSB regarding the financial
position and liquidity of the Company are forward-looking statements. Although
the Company believes that the expectations reflected in the forward-looking
statements are reasonable, it can give no assurance that such expectations will
prove to have been correct. Important factors regarding forward-looking
statements, including certain risks and uncertainties that could cause actual
results to differ materially from the Company's expectations, are disclosed in
this quarterly report on Form 10-QSB. The Company does not undertake any
obligation to publicly revise its forward-looking statements to reflect events
or circumstances that arise after the date of this quarterly report on Form
10-QSB.

Important factors that could cause actual results to differ materially from
those in the forward-looking statements in this quarterly report on Form 10-QSB
include changes from anticipated levels of operations, customer acceptance of
existing and new products, anticipated development schedules of new products,
anticipated levels of sales, future national or regional economic and
competitive conditions, changes in relationships with customers, access to
capital, casualty to or other disruption of the Company's production facility
and equipment, delays and disruptions in the shipment of the Company's products,
government regulations and the ability of the Company to meet its stated
business goals.

RESULTS OF OPERATIONS

THREE MONTHS ENDED SEPTEMBER 30, 2000 COMPARED TO THREE MONTHS ENDED SEPTEMBER
30, 1999

Sales. The Company's total sales decreased by $0.7 million, or 36%, to $1.2
million during the quarter ended September 30, 2000 from $1.9 million during the
quarter ended September 30, 1999. Sales at the Company's Intelli-Site, Inc.
subsidiary decreased from $0.4 million during the quarter ended September 30,
1999 to $0.1 million during the quarter ended September 30, 2000, primarily due
to a large end-user system installation project in the quarter ended September
30, 1999. In addition, sales at the Company's B&B Electromatic, Inc. subsidiary
decreased from $1.5 million in the quarter ended September 30, 1999 to $1.1
million in the quarter ended September 30, 2000, due to a decline in the volume
of road and bridge sales. For the quarter ended September 30, 2000,
approximately 90% of the Company's revenues were generated from the sale of
products manufactured by the Company, compared to 79% for the quarter ended
September 30, 1999.

Cost of Sales. Cost of sales as a percentage of sales increased to 75% for the
quarter ended September 30, 1999 from 62% for the quarter ended September 30,
2000. For the three months ended September 30, 2000, approximately 79% of the
Company's cost of sales were related to the products manufactured by the
Company, compared to 76% for the three months ended September 30, 1999.

Gross Margin. Gross margin as a percent of sales decreased to 25% for the
quarter ended September 30, 2000 from 38% for the quarter ended September 30,
1999. This decrease is due to a less favorable product mix at B&B and also due
to a decrease in end-user system installations and software sales at



                                  Page 8 of 12
<PAGE>   9


Intelli-Site. Software sales generally have higher gross margins than either end
user system installations or the B&B product line.

Selling, General and Administrative. Selling, general and administrative
expenses decreased by approximately 6% or $64,000 during the quarter ended
September 30, 2000 compared to the quarter ended September 30, 1999, primarily
due to the reallocation of programming personnel from the operations department
to the research and product development department at the Company's Intelli-Site
subsidiary.

Research and Product Development. Research and product development expenses
increased by approximately 59% or $54,000 during the quarter ended September 30,
2000 compared to the quarter ended September 30, 1999, due to the increased
expenditures at the Company's Intelli-Site subsidiary involved with hiring more
computer programmers for research and development.

Interest Expense. Interest expense increased by approximately $24,000 during the
quarter ended September 30, 2000 compared to the quarter ended September 30,
1999, due to incurring additional debt required to meet working capital needs.

LIQUIDITY AND CAPITAL RESOURCES

The Company's cash position increased by $3,559 during the first quarter of
fiscal year 2001, compared to the quarter ended September 30, 2000. At September
30, 2000, the Company had $103,195 in cash and cash equivalents and had $426,000
outstanding under its accounts receivable factoring facility. The factoring
facility, which is secured by accounts receivable and inventory, permits the
Company to borrow up to $0.8 million, subject to availability under its
borrowing base.

For the three months ended September 30, 2000, the Company's operating
activities used $426,293 of cash compared to $712,312 of cash used in operations
during the three months ended September 30, 1999. The decrease in cash used in
operations is primarily due to the collections of accounts receivable at the
Company's B&B subsidiary and the extended timing of payments to vendors.

The Company used $14,042 for the purchase of property and equipment during the
quarter ended September 30, 2000, compared to $17,436 for the quarter ended June
30, 2000.

During the quarter ended September 30, 2000, the Company financed its operations
with cash flows from long-term borrowings of $537,835 compared to $390,763
during the quarter ended June 30, 2000.

The Company made payments of $51,945 on debt and other liabilities during the
quarter ended September 30, 2000, compared to payments of $112,636 on debt and
other liabilities during the quarter ended June 30, 2000.

In November 2000, the Company entered into an agreement for a financial
restructuring plan with its two largest stockholders, Renaissance Capital Growth
& Income Fund III, Inc. and Renaissance US Growth and Income Trust PLC. Both of
these Renaissance entities are managed by Renaissance Capital Group, Inc. The
financial restructuring plan provides that the Renaissance entities will
exchange all their outstanding convertible debentures, convertible notes, notes,
and accrued interest into a new class of the Company's preferred stock.

The new class of the Company's preferred stock, Series G preferred stock, would
have approximately $6 million principal amount, a 5% dividend that accrues but
is not paid until redemption, and would be convertible into shares of the
Company's common stock at $.20 per share. The Series G preferred stock would be
redeemable in years three through five, or earlier from the proceeds of the sale
of certain assets.



                                  Page 9 of 12
<PAGE>   10
As part of the financial restructuring plan, Renaissance Capital Growth & Income
Fund III, Inc. and Renaissance US Growth and Income Trust PLC have agreed to
advance a combined $1 million in promissory notes to the Company in a private
placement. In the event the Company receives at least $100,000 in additional
subscriptions under this placement, the $1 million in promissory notes will be
exchangeable into the Company's Series F preferred stock. The Series F preferred
stock will have a 5% dividend, which accrues for two years, and is convertible
into common shares at $.20 per share. The promissory notes will mature 120 days
after the date of the promissory notes unless exchanged for the shares of the
Series F preferred stock.

The financial restructuring plan is subject to stockholder approval at the 2000
annual meeting of the stockholders. The Company currently does not have a
sufficient number of shares of Common Stock authorized to accommodate these
transactions. The Company will seek stockholder approval to amend its
certificate of incorporation to increase the number of authorized shares of
Common Stock.

The Company anticipates that it will receive a portion of the $1.0 million in
connection with the financial restructuring before the 2001 Annual Meeting of
Stockholders. The Company will receive the full amount of this $1.0 million in
funding before June 30, 2001. The cash that the Company receives from the
accounts receivable factoring facility is utilized to support Company-wide
operations. As discussed in more detail in the Company's proxy statement for the
2001 Annual Meeting of Stockholders, the Company's board of directors determined
that the proposed financial restructuring is the best alternative to attempt to
preserve stockholder value and to obtain additional funding. If the Company's
stockholders do not approve the proposed financial restructuring or if the
financial restructuring is not completed, then at the present time and the
foreseeable future, it seems unlikely that the Company will be able to obtain
additional financing either through the sale of assets of the Company or its
subsidiaries, equity placement and/or additional debt.

The Company's backlog is calculated as the aggregate sales prices of firm orders
received from customers less revenue recognized. At November 30, 2000, the
Company's backlog was approximately $1.4 million. The Company expects that it
will fill the majority of this backlog by December 31, 2001.



                                 Page 10 of 12
<PAGE>   11


                           PART II. OTHER INFORMATION

Item 1. Legal Proceedings.

None.

Item 2.  Changes in Securities.

None.

Item 3.  Defaults Upon Senior Securities.

In the fall of 1998, the Company needed additional funding as a result of
continuing operating losses. Renaissance Capital Growth & Income Fund III, Inc.
and Renaissance US Growth & Income Trust PLC loaned the Company additional funds
in exchange for convertible debt instruments. In March 1998 the conversion rate
on the Renaissance convertible debentures was reduced to $0.549. The Renaissance
convertible debentures have an interest rate of 9% of outstanding principal
balance and are due in monthly installments though December 2003. Monthly
principal installments are $10 per $1,000 of the then remaining principal amount
of the debenture and were to commence beginning in December 1999 through
maturity. These principal payments have not yet begun. These debentures are
secured by equity, assets and future contracts.

The Company is in default of the covenants for the convertible debentures issued
to Renaissance Capital Growth & Income Fund III, Inc. and Renaissance US Growth
& Income Trust PLC. At December 31, 2000, the principal amount of these
convertible debentures in default was $4.6 million, of which $510,517 is
currently outstanding. The Company has not received notice of default and is
currently in negotiations to restructure this debt, but no agreement has yet
been reached. The Company currently has no other source of repayment and there
can be no assurance that these renegotiations will be successful. Accordingly,
the debentures are classified as short-term debt on the financial statements.

Item 4.  Submission of Matters to a Vote of Security Holders.

None.

Item 5.  Other Information.

None.

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

(a)      Exhibits

         None.

(b) Reports filed on Form 8-K.

         The Company filed a Form 8-K on August 25, 2000 to report the changes
in the Company's management.



                                 Page 11 of 12
<PAGE>   12


                                   SIGNATURES

         In accordance with the requirements of the Exchange Act, the registrant
caused this report to be signed on its behalf by the undersigned, thereunto duly
authorized.

                                 Integrated Security Systems, Inc.
                                 ---------------------------------
                                            (Registrant)



Date: February 28, 2001          /s/ C. A. RUNDELL, JR.
                                 ----------------------
                                 C. A. Rundell, Jr.
                                 Director, Chairman of the Board, and Chief
                                 Executive Officer (Principal Executive Officer)


Date: February 28, 2001          /s/ HOLLY J. BURLAGE
                                 --------------------
                                 Holly J. Burlage
                                 Executive Vice President, Chief Financial
                                 Officer, Secretary and Treasurer (Principal
                                 Accounting and Financial Officer)