<PAGE>   1


                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                   FORM 10-Q/A

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

                 For the quarterly period ended March 31, 1996.

                                       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 0-21042
                                                -------

                          Molten Metal Technology, Inc.
                          -----------------------------
             (Exact name of registrant as specified in its charter)


              Delaware                                  52-1659959
              --------                                  ----------
  (State or other jurisdiction of           (I.R.S. Employer Identification No.)
   incorporation or organization)


          400-2 Totten Pond Road
               Waltham, MA                                     02154
               -----------                                     -----
  (Address of principal executive offices)                   (Zip Code)


Registrant's telephone number, including area code:         (617) 487-9700

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, and (2) has been subject to such filing requirements
for the past 90 days.

                                    YES   X   NO
                                       ------    -------

Indicate the number of shares outstanding of each of the issuer's classes of
common stock, as of the latest practicable date.

  Common Stock, $.01 par value                             23,487,252
  ----------------------------                   ------------------------------
             Class                               Outstanding at August 12, 1996


<PAGE>   2


                 MOLTEN METAL TECHNOLOGY, INC. AND SUBSIDIARIES
<TABLE>

                                         CONSOLIDATED BALANCE SHEET
<CAPTION>


                                                                                MARCH 31,            DECEMBER 31,
                                                                                  1996                   1995              
                                                                                 ----                   ----                 

<S>                                                                           <C>                   <C>         
ASSETS

Current assets:
  Cash and cash equivalents                                                   $ 15,126,285          $  6,644,856
  Short-term investments                                                        68,432,802            79,631,394
  Accounts receivable                                                            1,221,771             1,917,858
  Accounts receivable from affiliate                                            20,043,269            15,412,196
  Prepaid expenses and other current assets                                      3,111,215             2,309,398
                                                                              ------------          ------------
          Total current assets                                                 107,935,342           105,915,702

Restricted cash and investments                                                  5,696,477             7,432,817
Fixed assets, net                                                               39,975,106            34,679,390
Intangible assets, net                                                           3,945,271             3,501,680
Investment in affiliate                                                          1,204,106               834,794
Other assets                                                                     1,360,743               971,618
                                                                              ------------          ------------
                                                                              $160,117,045          $153,336,001
                                                                              ============          ============

LIABILITIES AND STOCKHOLDERS' EQUITY

Current liabilities:
  Current portion of long-term debt                                           $    195,043          $    195,043
  Accounts payable                                                              14,147,330             9,827,490
  Accrued expenses                                                               2,963,891             1,713,557
  Accrued interest                                                                 315,773               789,455
  Deferred revenue from affiliate                                                2,333,333             4,083,334
                                                                              ------------          ------------
          Total current liabilities                                             19,955,370            16,608,879
                                                                              ------------          ------------

Long-term debt                                                                  22,836,249            22,883,962
                                                                              ------------          ------------
Due to related parties                                                           1,474,586             1,474,586
                                                                              ------------          ------------
Deferred income from affiliate                                                   4,413,363             2,459,918
                                                                              ------------          ------------

Stockholders' equity:
  Preferred stock, $.01 par value, 3,000 shares authorized, no shares
     issued or outstanding                                                              --                    --
  Common stock, $.01 par value, 40,000,000 shares authorized; shares
     issued and outstanding: 23,057,330 at March 31, 1996 and
      22,746,854 at December 31, 1995                                              230,573               227,469
  Additional paid-in capital                                                   148,206,109           146,641,721
  Valuation allowance for short-term investments                                  (575,686)             (311,163)
  Accumulated deficit                                                          (36,423,519)          (36,638,947)
                                                                              ------------          ------------
                                                                               111,437,477           109,919,080
  Less: Deferred compensation                                                           --               (10,424)
                                                                              ------------          ------------
          Total stockholders' equity                                           111,437,477           109,908,656
                                                                              ------------          ------------

                                                                              $160,117,045          $153,336,001
                                                                              ============          ============
</TABLE>

                       See notes to financial statements.

 
                                      3

<PAGE>   3


                 MOLTEN METAL TECHNOLOGY, INC. AND SUBSIDIARIES
<TABLE>

                             CONSOLIDATED STATEMENT OF OPERATIONS
<CAPTION>

                                                                                  QUARTER ENDED MARCH 31,
                                                                              -------------------------------
                                                                                 1996                 1995
                                                                                 ----                 ----

<S>                                                                           <C>                 <C>        
Revenue:
    Research and development ("R&D")                                          $ 1,257,808         $ 2,642,194
    Construction, R&D and consulting from affiliate                            17,365,736             233,503
    Technology transfer from affiliate                                          3,750,000           1,750,000
                                                                              -----------         -----------
                                                                               22,373,544           4,625,697
                                                                              -----------         -----------

Operating expenses:
    Cost of revenue - R&D                                                       1,178,331           2,642,194
    Cost of revenue - construction, R&D and consulting from affiliate          15,144,941             251,473
    R&D                                                                         4,708,163           3,687,455
    Selling, general and administrative ("SG&A")                                2,418,332           1,941,520
                                                                              -----------         -----------
                                                                               23,449,767           8,522,642
Equity income from affiliate                                                      369,312                --
                                                                              -----------         -----------
Loss from operations                                                             (706,911)         (3,896,945)

Other income (expense):
    Interest income                                                             1,354,729           1,372,274
    Interest expense                                                             (432,390)           (479,121)
                                                                              -----------         -----------
Net income (loss)                                                             $   215,428         $(3,003,792)
                                                                              ===========         =========== 

Net income (loss) per share                                                   $      0.01         $     (0.14)
                                                                              ===========         =========== 

Weighted average common and common equivalent
 shares outstanding                                                            27,493,890          22,201,430
                                                                              ===========         =========== 
</TABLE>

                       See notes to financial statements.


                                       4
<PAGE>   4


                 MOLTEN METAL TECHNOLOGY, INC. AND SUBSIDIARIES

<TABLE>

                          CONSOLIDATED STATEMENT OF CASH FLOWS

<CAPTION>


                                                                          QUARTER ENDED MARCH 31,
                                                                     --------------------------------
                                                                        1996                  1995
                                                                        ----                  ----

<S>                                                                  <C>                  <C>         
Cash flows from operating activities:
 Net income (loss)                                                   $   215,428          $(3,003,792)
 Adjustments to reconcile net income (loss) to net cash
 provided by (used in) operating activities:
   Depreciation and amortization                                       1,316,704            1,281,661
   Equity income from affiliate                                         (369,312)                  --
   Compensation expense related to common stock option                    10,424               15,624
   Decrease (increase) in accounts receivable                            696,087           (2,642,194)
   Decrease (increase) in accounts receivable from affiliate          (4,631,073)              85,462
   Increase in prepaid expenses and other current assets                (801,817)            (750,327)
   Increase in other assets                                             (401,696)              (9,447)
   Increase in accounts payable                                        4,319,840              287,010
   Increase in accrued expenses                                        1,250,334              805,522
   Decrease in accrued interest                                         (473,682)            (468,333)
   Decrease in deferred revenue                                       (1,750,001)          (1,750,000)
   Increase in deferred income                                         1,953,445                   --
                                                                     -----------          ----------- 
       Net cash provided by (used in) operating activities             1,334,681           (6,148,814)
                                                                     -----------          ----------- 

Cash flows from investing activities:
  Purchase of fixed assets                                            (6,544,481)          (2,244,104)
  Purchase of intangible assets                                         (498,959)            (249,092)
  Redemption of short-term investments, net                           10,934,069           10,040,752
  Decrease in restricted cash                                          1,736,340               59,581
                                                                     -----------          ----------- 
      Net cash provided by investing activities                        5,626,969            7,607,137
                                                                     -----------          ----------- 

Cash flows from financing activities:
  Proceeds from issuances of common stock                              1,567,492              150,532
  Principal repayments of long-term debt                                 (47,713)             (48,495)
                                                                     -----------          ----------- 
      Net cash provided by financing activities                        1,519,779              102,037
                                                                     -----------          ----------- 
Increase in cash and cash equivalents                                  8,481,429            1,560,360
Cash and cash equivalents at beginning of period                       6,644,856           12,063,883
                                                                     -----------          ----------- 
Cash and cash equivalents at end of period                           $15,126,285          $13,624,243
                                                                     ===========          ===========
</TABLE>

                       See notes to financial statements.


                                       5

<PAGE>   5


                 MOLTEN METAL TECHNOLOGY, INC. AND SUBSIDIARIES
                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

NOTE 1. BASIS OF PRESENTATION

Molten Metal Technology, Inc. (the "Company") is an environmental technology
company commercializing pollution prevention and waste recycling methods that
are broadly applicable to a wide variety of hazardous, non-hazardous and
radioactive wastes. The Company developed its core technology, Catalytic
Extraction Processing ("CEP"), to dissolve waste compounds to their constituent
elements in a molten metal bath and reconfigure the elements into useful raw
materials.

The consolidated financial statements include the accounts of the Company and
its wholly owned subsidiaries. All significant intercompany balances and
transactions have been eliminated in consolidation.

Net income (loss) per share is determined by dividing net income (loss) by the
weighted average number of common and common equivalent shares outstanding
during the period. Common share equivalents consist of common stock which may be
issuable upon exercise of outstanding stock options and warrants. Common share
equivalents have been excluded from the weighted average number of common shares
in loss periods since their effect is anti-dilutive.

Certain reclassifications have been made for consistent presentation. The
reclassifications have no effect on the net loss for the period ending March 31,
1995.

The information furnished is unaudited and reflects all adjustments (consisting
of only normal recurring adjustments) which, in the opinion of management, are
necessary for a fair presentation of the financial position and results of
operations for the interim periods. The accompanying financial statements should
be read in conjunction with the Company's audited financial statements and
related footnotes for the year ended December 31, 1995 which are included in the
Company's annual report on Form 10-K for the year ended December 31, 1995. The
results of operations for the quarter ended March 31, 1996 are not necessarily
indicative of the results to be expected for the full year.

NOTE 2. EQUITY TRANSACTIONS

During the quarter ended March 31, 1996, 310,476 shares of common stock were
issued upon the exercise of options.

                                       6
<PAGE>   6


NOTE 3. EXPANSION OF PARTNERSHIP

In March 1996, the Company and Lockheed Martin Corporation("LMC") executed an
agreement to expand their partnership (M4 Environmental L.P. or "M4") through
the acquisition by M4 of the Retech division of Lockheed Environmental Systems &
Technologies Co., an indirect wholly-owned subsidiary of LMC. The Retech
division designs and manufactures metallurgical equipment and waste processing
systems that utilize a plasma technology. Under this agreement, LMC contributed
approximately half of the assets of the Retech division to M4, and the Company
purchased substantially all of the remaining assets of the Retech division for
307,735 shares of its common stock, and then immediately contributed these
assets to M4. Pursuant to the agreement, the number of shares issued to LMC will
be adjusted based on information to be included in the closing balance sheet of
Retech. In addition, the Company and LMC agreed to restructure certain aspects
of their joint venture agreement. LMC has increased its equity commitment to M4
from $50 million to $75 million, has agreed to provide up to $150 million in
project debt guarantees for M4 CEP projects through 2004, subject to various
conditions, and has agreed to provide a $15 million working capital facility to
M4. The expanded M4 Partnership will continue to be owned by the Company and LMC
on a 50/50 basis. As part of this restructuring, M4 and LMC have agreed to
"team" in response to certain major procurement opportunities for the Department
of Defense, the Department of Energy and the United States Enrichment
Corporation. Under this teaming arrangement, LMC, through its Energy and
Environmental Sector ("LMC/EES"), would serve as the prime contractor, with
responsibility for overall contract management and customer interface, and M4
would be responsible for providing and managing all waste processing
technologies necessary to perform the teamed project. Also, M4 will have the
right to fulfill LMC's other waste processing requirements, subject to certain
limitations.

The Company accounts for its investment in M4 using the equity method. During
the quarter ended March 31, 1996, the Company recognized approximately $369,000
in equity income from M4, reflecting the Company's share of revenues earned by
M4. Under the partnership agreement, the Company and LMC share equally in M4's
revenues and all expenses are allocated to LMC until the capital accounts of the
Company and LMC are equal. Thereafter, the Company and LMC will share equally in
the profits or losses of M4. The Company anticipates that its capital account
will become equal to LMC's capital account within one year. The related effect
on the Company's equity in income of M4 could have a material adverse effect on
future results of operations.

NOTE 4. SUBSEQUENT EVENT

In May 1996, the Company issued $143,750,000 of Convertible Subordinated Notes
Due 2006 (the "Notes"). The Notes have a term of ten years and bear interest at
the rate of 5.50% per year. The Notes are convertible into shares of the
Company's common stock 


                                       7
<PAGE>   7



at a conversion price of $38.75 per share, which represents a 25% premium over
the closing price of the Company's common stock on April 25, 1996.

NOTE 5. NEW ACCOUNTING PRONOUNCEMENT

Effective January 1, 1996, the Company adopted Statement of Financial Accounting
Standards No. 121, `Accounting for the Impairment of Long-Lived Assets and for
Long-Lived Assets to Be Disposed Of' ("FAS 121"). In accordance with this
standard, the Company periodically assesses whether any events or changes in
circumstances have occurred that would indicate that the carrying amount of a
long-lived asset may not be recoverable. If such an event or change in
circumstance occurs, the Company will evaluate whether the carrying amount of
such assets is recoverable by comparing the net book value of the assets to
estimated future undiscounted cash flows, excluding interest charges,
attributable to such assets. If it is determined that the carrying amount is not
recoverable, the Company will recognize an impairment loss equal to the excess
of the carrying amount of the asset over its fair value. Adoption of FAS 121 did
not have an impact on the Company's financial statements.


                                       8
<PAGE>   8


                                   SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the
Registrant has duly caused this amended report to be signed on its behalf by the
undersigned thereunto duly authorized.



                                           MOLTEN METAL TECHNOLOGY, INC.



Date:      November 18, 1996           By: /s/ Benjamin T. Downs
           -----------------               -----------------------------------
                                           Benjamin T. Downs
                                           Executive Vice President of Finance
                                           and Administration, Treasurer
                                           (Principal Financial Officer and
                                           Authorized Signatory)



                                       9