<PAGE>

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                      SECURITIES AND EXCHANGE COMMISSION
                            Washington, D.C. 20549

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

                                   FORM 10-Q/A
                               (Amendment No. 1)

(Mark One)

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

   For the quarterly period ended September 30, 2001

                                      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 000-31103

                               LEXAR MEDIA, INC.
            (Exact name of registrant as specified in its charter)

                      Delaware                           33-0723123
           (State or other jurisdiction of            (I.R.S. Employer
           incorporation or organization)            Identification No.)

                47421 Bayside Parkway
                 Fremont, California                        94538
      (Address of principal executive offices)           (Zip Code)

                                (510) 413-1200
             (Registrant's telephone number, including area code)

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

   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 [_]

Number of shares of common stock outstanding as of October 31, 2001: 59,759,448

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<PAGE>

                               LEXAR MEDIA, INC.

                                   FORM 10-Q/A
                   FOR THE QUARTER ENDED SEPTEMBER 30, 2001

                                EXPLANATORY NOTE

The Registrant hereby amends Part I - Item 1--"Financial Statements" contained
in the Registrant's Quarterly Report on Form 10-Q for the quarterly period ended
September 30, 2001 to correct an error with respect to the "Accounts payable and
accrued liabilities" line item within "Net cash used in operating activities"
for the nine months ended September 30, 2001, as set forth in its Condensed
Consolidated Statements of Cash Flows. The Registrant's total net cash used in
operating activities for the nine months ended September 30, 2001 remains as
originally reported. Except as set forth above, all information contained in the
originally filed Quarterly Report on Form 10-Q is presented as of the original
filing date, and has not been updated in this amended filing.

<PAGE>

PART I -- FINANCIAL INFORMATION

1. Financial Statements

                      LEXAR MEDIA, INC. AND SUBSIDIARIES

                     CONDENSED CONSOLIDATED BALANCE SHEETS
                (in thousands, except share and per share data)
                                  (unaudited)

<TABLE>
<CAPTION>
                                                                              September 30, December 31,
                                                                                  2001          2000
                                                                              ------------- ------------
                                   ASSETS
                                   ------
<S>                                                                           <C>           <C>
Current assets:
   Cash and cash equivalents (includes restricted cash of $2,333 and $1,000).   $  14,980     $  8,755
   Short-term investments....................................................          --       19,987
   Accounts receivable, net..................................................       9,586        8,767
   Inventory.................................................................       6,545       27,536
   Prepaid expenses and other current assets.................................       1,138        1,909
                                                                                ---------     --------
       Total current assets..................................................      32,249       66,954
Property and equipment, net..................................................       2,622        3,364
Intangible assets, net.......................................................         291        3,544
Other assets.................................................................         863          986
                                                                                ---------     --------
       Total assets..........................................................   $  36,025     $ 74,848
                                                                                =========     ========
<CAPTION>

                    LIABILITIES AND STOCKHOLDERS' EQUITY
                    ------------------------------------
<S>                                                                           <C>           <C>
Current liabilities:
   Accounts payable..........................................................   $   7,102     $  8,007
   Accrued liabilities.......................................................       8,162        8,886
   Deferred revenue..........................................................       7,080          446
   Notes payable to stockholders.............................................         187          362
   Notes payable to banks....................................................       4,909        6,088
                                                                                ---------     --------
       Total current liabilities.............................................      27,440       23,789
Notes payable to stockholders, net of current portion........................          --          159
Notes payable, net...........................................................          --        1,362
                                                                                ---------     --------
       Total liabilities.....................................................      27,440       25,310

Stockholders' equity:
Common stock, $0.0001 par value:
   75,000,000 shares authorized; 59,754,929 and 60,052,462 shares issued and
     outstanding.............................................................           6            6
   Additional paid-in capital................................................     147,611      152,796
   Unearned stock-based compensation.........................................      (2,567)      (9,586)
   Notes receivable from stockholders........................................      (3,593)      (5,292)
   Accumulated deficit.......................................................    (132,750)     (88,348)
   Accumulated other comprehensive loss......................................        (122)         (38)
                                                                                ---------     --------
       Total stockholders' equity............................................       8,585       49,538
                                                                                ---------     --------
       Total liabilities and stockholders' equity............................   $  36,025     $ 74,848
                                                                                =========     ========
</TABLE>

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

                                      1

<PAGE>

                      LEXAR MEDIA, INC. AND SUBSIDIARIES

                CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS
                   (in thousands, except per share amounts)
                                  (unaudited)

<TABLE>
<CAPTION>
                                                         Three Months Ended           Nine Months Ended
                                                     --------------------------  --------------------------
                                                     September 30, September 30, September 30, September 30,
                                                         2001          2000          2001          2000
                                                     ------------- ------------- ------------- -------------
<S>                                                  <C>           <C>           <C>           <C>
Revenues:
   Product revenues.................................    $14,319      $ 30,724      $ 43,870      $ 71,290
   License and royalty revenues.....................      3,829           250         7,838           500
                                                        -------      --------      --------      --------
       Total revenues...............................     18,148        30,974        51,708        71,790
Cost of product revenues (excludes stock-based
  compensation of $(16), $(475), $35, and $291).....     12,942        25,852        53,061        59,904
                                                        -------      --------      --------      --------
Gross margin........................................      5,206         5,122        (1,353)       11,886
                                                        -------      --------      --------      --------
Operating expenses:
   Research and development (excludes stock-based
     compensation of $322, $1,018, $1,028 and
     $3,724)........................................      1,215         1,701         4,421         5,252
   Sales and marketing (excludes stock-based
     compensation of $87, $499, $232 and
     $1,685)........................................      4,167         5,957        16,151        14,083
   General and administrative (excludes stock-based
     compensation of $(459), $1,723, $554 and
     $5,233)........................................      2,500         3,769        10,171         9,629
   Goodwill impairment..............................         --            --         2,854            --
   Restructuring charge.............................         --            --         2,086            --
   Stock-based compensation.........................        (66)        2,765         1,849        10,933
                                                        -------      --------      --------      --------
       Total operating expenses.....................      7,816        14,192        37,532        39,897
                                                        -------      --------      --------      --------
Loss from operations................................     (2,610)       (9,070)      (38,885)      (28,011)
Other income and expense:
   Interest and other expense.......................       (545)       (6,067)       (3,911)       (6,545)
   Interest and other income........................        144           615           868           992
   Foreign exchange gain (loss).....................        194           250          (198)          193
                                                        -------      --------      --------      --------
       Total other expense..........................       (207)       (5,202)       (3,241)       (5,360)
                                                        -------      --------      --------      --------
Loss before income taxes............................     (2,817)      (14,272)      (42,126)      (33,371)
Income tax expense..................................        676            --         2,276            --
                                                        -------      --------      --------      --------
       Net loss.....................................    $(3,493)     $(14,272)     $(44,402)     $(33,371)
                                                        =======      ========      ========      ========
Net loss per common share--basic and diluted........    $ (0.06)     $  (0.46)     $  (0.77)     $  (2.12)
                                                        =======      ========      ========      ========
Shares used in net loss per common share
  calculation--basic and diluted....................     58,547        30,985        57,912        15,976
                                                        =======      ========      ========      ========
</TABLE>

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

                                      2

<PAGE>

                      LEXAR MEDIA, INC. AND SUBSIDIARIES

                CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS
                                (in thousands)
                                  (unaudited)

<TABLE>
<CAPTION>
                                                                                                      Nine Months Ended
                                                                                                 --------------------------
                                                                                                 September 30, September 30,
                                                                                                     2001          2000
                                                                                                 ------------- -------------
<S>                                                                                              <C>           <C>
Cash flows from operating activities:
    Net loss....................................................................................   $(44,402)     $(33,371)
    Adjustments to reconcile net loss to net cash used in operating activities:
       Depreciation and amortization............................................................      1,461         1,376
       Issuance of warrants and stock to non-employees..........................................         51           167
       Goodwill impairment......................................................................      2,854            --
       Restructuring charge.....................................................................      1,590            --
       Loss on disposition of fixed assets......................................................          6            --
       Amortization of stock-based compensation.................................................      1,849        10,933
       Imputed and other non-cash interest......................................................      2,991         5,647
       Change in operating assets and liabilities:
          Accounts receivable, net..............................................................       (819)       (6,139)
          Inventory.............................................................................     20,991        (3,244)
          Prepaid expenses and other assets.....................................................        264        (2,052)
          Accounts payable and accrued liabilities..............................................     (2,684)        4,928
          Deferred revenue......................................................................      6,834           885
                                                                                                   --------      --------
             Net cash used in operating activities..............................................     (9,014)      (20,870)
                                                                                                   --------      --------
Cash flows from investing activities:
    Purchase of property and equipment..........................................................       (856)       (2,035)
    Cash used in acquisition of Impact Peripherals, Ltd.........................................         --           (64)
    Cash acquired upon acquisition of Printroom.com, Inc........................................         --            49
    Purchase of short-term investments..........................................................         --       (19,692)
    Proceeds from sale of short-term investments................................................     19,987         3,896
                                                                                                   --------      --------
             Net cash provided by (used in) investing activities................................     19,131       (17,846)
                                                                                                   --------      --------
Cash flows from financing activities:
    Proceeds from initial public offering, net of issuance costs................................         --        53,350
    Issuance of stock under employee stock purchase plan........................................        392            --
    Exercise of stock options and warrants......................................................         45           754
    Repayment of notes payable..................................................................     (6,445)      (18,486)
    Proceeds from notes payable.................................................................      2,000        12,125
    Repayment of notes receivable from stockholders.............................................        220            --
    Proceeds from notes payable to stockholders.................................................         --        13,275
    Repurchase of stock.........................................................................        (20)          (19)
                                                                                                   --------      --------
             Net cash (used in) provided by financing activities................................     (3,808)       60,999
                                                                                                   --------      --------
    Effect of exchange rates on cash and cash equivalents.......................................        (84)          (25)
                                                                                                   --------      --------
Net increase in cash and cash equivalents.......................................................      6,225        22,258
Cash and cash equivalents at beginning of period................................................      8,755         6,495
                                                                                                   --------      --------
Cash and cash equivalents at end of period......................................................   $ 14,980      $ 28,753
                                                                                                   ========      ========
Supplemental disclosure of non-cash financing and investing activities:
    Conversion of note payable into common stock................................................   $     --      $  2,000
    Re-pricing of warrants in connection with amended credit facility agreement.................   $    792            --
    Exercise of stock options and restricted stock grants in exchange for full recourse notes
     receivable.................................................................................         --      $  3,536
    Issuance of warrants in relation to credit facilities.......................................         --      $  3,140
    Issuance of common stock in connection with acquisition of Printroom.com, Inc. and
     Impact Peripherals, Ltd....................................................................         --      $  4,040
    Repurchase of common stock by cancellation of notes receivable..............................   $  1,479      $    190
    Issuance of warrant in connection with license and royalty agreement........................   $    206            --
    Issuance of common stock for browser development............................................         --      $    200
    Conversion of preferred stock into common stock.............................................         --      $ 53,415
</TABLE>

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

                                      3

<PAGE>

                      LEXAR MEDIA, INC. AND SUBSIDIARIES

             NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS

Note 1--Basis of Presentation

   The accompanying unaudited condensed consolidated financial statements have
been prepared by Lexar Media, Inc. (the "Company") in accordance with generally
accepted accounting principles for interim financial information and with the
instructions to Form 10-Q and Regulation S-X. 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
normally recurring adjustments considered necessary for a fair presentation
have been included. In addition, certain reclassifications have been made to
prior year balances in order to conform to the current year presentation.

   The financial statements should be read in conjunction with the audited
consolidated financial statements for the year ended December 31, 2000 included
in our Annual Report on Form 10-K, as filed with the Securities and Exchange
Commission on April 2, 2001. The condensed consolidated balance sheet data as
of December 31, 2000 was derived from the audited financial statements.

   The results of operations for the three and nine months ended September 30,
2001 are not necessarily indicative of results that may be expected for any
other future period, including the full fiscal year.

Note 2--Summary of Selected Accounting Policies

  Revenue recognition

   The Company's customers include distributors, retailers, original equipment
manufacturers and end users. Certain customers have return and price protection
rights. The Company recognizes revenue where there is a contract or purchase
order, upon shipment or delivery depending on the terms of sale, and where
collectibility of the resulting receivable is reasonably assured. The Company
provides for estimated future returns and price protection based on historical
experience at the time revenue is recognized. At the time of sale, the Company
also provides for the estimated costs of meeting product warranty obligations.
For certain customers where the Company is unable to reasonably estimate the
level of returns or where the customers do not take title to the product on
delivery, revenues and the costs of revenues are deferred until these customers
have sold the product to their customers.

  Accounting for stock-based compensation

   The Company accounts for employee stock-based compensation arrangements in
accordance with the provisions of Accounting Principles Board Opinion ("APB")
No. 25, "Accounting for Stock Issued to Employees," Financial Accounting
Standards Board Interpretation ("FIN") No. 44, "Accounting for Certain
Transactions Involving Stock Compensation--an Interpretation of APB 25," the
Emerging Issues Task Force ("EITF") 00-23, "Issues Related to the Accounting
for Stock Compensation under APB Opinion No. 25 and FIN No. 44," and FIN No.
28, "Accounting for Stock Appreciation Rights and Other Variable Stock Option
or Award Plans," and complies with the disclosure provisions of Statement of
Financial Accounting Standards ("SFAS") No. 123, "Accounting for Stock-Based
Compensation." Under APB No. 25, compensation expense is based on the
difference, if any, on the date of grant, between the estimated fair value of
the Company's common stock and the exercise price of the option. SFAS No. 123
defines a "fair value" based method of accounting for an employee stock option
or similar equity investment. The Company accounts for equity instruments
issued to non-employees in accordance with the provisions of SFAS No. 123 and
EITF 96-18, "Accounting for Equity Instruments That Are Issued to Other Than
Employees for Acquiring, or in Conjunction with Selling, Goods or Services."

                                      4

<PAGE>

                      LEXAR MEDIA, INC. AND SUBSIDIARIES

       NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS--(Continued)


  Recent accounting developments

   In July 2001, the Financial Accounting Standards Board ("FASB") issued
Statement of Financial Accounting Standards No. 141 ("SFAS 141"), "Business
Combinations." SFAS 141 requires the purchase method of accounting for business
combinations initiated after June 30, 2001, and eliminates the pooling-of
interests method. The Company believes that the adoption of SFAS 141 will not
have a significant impact on its financial statements.

   In July 2001, the FASB issued Statement of Financial Accounting Standards
No. 142 ("SFAS 142"), "Goodwill and Other Intangible Assets," which is
effective for fiscal years beginning after December 15, 2001. SFAS 142
requires, among other things, the discontinuance of goodwill amortization. In
addition, the standard includes provisions upon adoption for the
reclassification of certain existing recognized intangibles as goodwill,
reassessment of the useful lives of existing recognized intangibles,
reclassification of certain intangibles out of previously reported goodwill and
the testing for impairment of existing goodwill and other intangibles. The
Company is currently assessing but has not yet determined the impact of SFAS
142 on its financial position and results of operations.

   In October 2001, the FASB issued SFAS No. 144, "Accounting for the
Impairment or Disposal of Long-Lived Assets." SFAS No. 144 supersedes SFAS No.
121, "Accounting for the Impairment of Long-Lived Assets and for Long-Lived
Assets to be Disposed of." SFAS No. 144 applies to all long-lived assets
(including discontinued operations) and consequently amends APB No. 30,
"Reporting the Results of Operations--Reporting the Effects of Disposal of a
Division of a Business." SFAS No. 144 develops one accounting model for
long-lived assets that are to be disposed of by sale and requires the
measurement to be at the lower of book value or fair value, less the cost to
sell the assets. Additionally, SFAS No. 144 expands the scope of discontinued
operations to include all components of an entity with operations that (1) can
be distinguished from the rest of the entity and (2) will be eliminated from
the ongoing operations of the entity in a disposal transaction. SFAS No. 144 is
effective for fiscal years beginning after December 15, 2001. The provisions of
SFAS No. 144 are not expected to have a significant impact on the Company's
financial position or operating results.

  Shipping and handling costs

   Shipping and handling costs associated with our product revenues are
included in selling and marketing expenses in the Company's condensed
consolidated statements of operations. These costs were $0.5 million and $0.3
million for the three months ended September 30, 2001 and September 30, 2000,
respectively, and $1.4 million and $0.8 million for the nine months ended
September 30, 2001 and September 30, 2000, respectively.

Note 3--Balance Sheet Detail (in thousands)

<TABLE>
<CAPTION>
                                        September 30, December 31,
                                            2001          2000
                                        ------------- ------------
              <S>                       <C>           <C>
              Inventories:
                 Raw materials.........    $  873       $ 4,897
                 Controllers...........       693         1,483
                 Flash memory products.     3,983        19,183
                 Ancillary products....       996         1,973
                                           ------       -------
                                           $6,545       $27,536
                                           ======       =======
</TABLE>

                                      5

<PAGE>

                      LEXAR MEDIA, INC. AND SUBSIDIARIES

       NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS--(Continued)


Note 4--Net Loss Per Common Share (in thousands, except per share date)

<TABLE>
<CAPTION>
                                                Three Months Ended           Nine Months Ended
                                            --------------------------  --------------------------
                                            September 30, September 30, September 30, September 30,
                                                2001          2000          2001          2000
                                            ------------- ------------- ------------- -------------
<S>                                         <C>           <C>           <C>           <C>
Numerator:
   Net loss................................    $(3,493)     $(14,272)     $(44,402)     $(33,371)
   Accretion of mandatorily redeemable
     convertible preferred stock...........         --           (72)           --          (423)
                                               -------      --------      --------      --------
   Net loss after accretion of mandatorily
     redeemable convertible preferred
     stock.................................    $(3,493)     $(14,344)     $(44,402)     $(33,794)
                                               =======      ========      ========      ========
Denominator:
   Weighted average common shares
     outstanding...........................     60,420        36,200        60,290        21,785
   Weighted average unvested common
     shares subject to repurchase..........     (1,873)       (5,215)       (2,378)       (5,809)
                                               -------      --------      --------      --------
   Denominator for basic and diluted
     calculations..........................     58,547        30,985        57,912        15,976
                                               =======      ========      ========      ========
   Net loss per common share, basic and
     diluted...............................    $ (0.06)     $  (0.46)     $  (0.77)     $  (2.12)
                                               =======      ========      ========      ========
</TABLE>

   All outstanding shares under options, warrants and convertible preferred
stock during each period have been excluded since they are anti-dilutive.

Note 5--Restructuring

   At the end of the second quarter of fiscal 2001, the Company decided to
implement a 27% reduction in its work force and to discontinue its
Printroom.com operations. The Company recognized a $2.1 million restructuring
charge in the second quarter of 2001 related to this restructuring. The
restructuring was effected in the third quarter of fiscal 2001 and is
substantially complete. The disposition of Printroom.com was implemented
through a sale of the Printroom.com assets to a company owned by the management
of Printroom.com.

   The following table depicts the restructuring and other activity through
September 30, 2001:

<TABLE>
<CAPTION>
                                         Accrued                        Accrued
                                        Balance at                    Balance at
                                         June 30,    Cash   Non-cash September 30,
                                           2001    Payments Charges      2001
                                        ---------- -------- -------- -------------
<S>                                     <C>        <C>      <C>      <C>
Reduction in workforce.................   $1,052    $(448)   $  --      $  604
Asset write-offs.......................      554       --     (536)         18
Excess facilities and related costs....      368      (28)      --         340
Other..................................      112      (20)      --          92
                                          ------    -----    -----      ------
                                          $2,086    $(496)   $(536)     $1,054
                                          ======    =====    =====      ======
</TABLE>

   Remaining expenditures relating to workforce reductions and termination
agreements will be substantially paid in the fourth quarter of 2001 and the
first quarter of 2002. Amounts related to excess facilities and related costs
are expected to be paid over the lease terms which expire in 2004.

                                      6

<PAGE>

                      LEXAR MEDIA, INC. AND SUBSIDIARIES

       NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS--(Continued)


Note 6--Notes Payable

   During September 2001, the Company established a new asset based credit
facility with Greater Bay Bancorp "GBB." The Company borrowed $2.0 million
under this facility at the end of the third quarter. The new facility bears
interest at an annual rate of 9.6%, plus administrative charges, has a term of
one year and is renewable from year to year thereafter. In addition, the
Company issued to GBB a warrant to purchase 250,000 shares of the Company's
common stock at an exercise price of $1.26 per share. The warrant was valued
using the Black-Scholes model at $0.1 million and recognized as an expense
during the third quarter. This facility may be terminated by either party, at
any time, upon 30 days notice.

   In October 2001, the Company elected to repay the outstanding balance on the
Access Technology Partners credit facility. Under the terms of the credit
facility, the repayment of the initial borrowing of $4.0 million was due in
June 2003. The principal payment made in October 2001 was $4.7 million, and the
Company wrote off the related unamortized warrant value and fees totaling $2.0
million.

Note 7--Comprehensive Loss

   Other comprehensive loss for the third quarter and first nine months of 2001
was $82,000 and $84,000, respectively. This loss was attributable to foreign
currency translation. There was no other comprehensive income or loss for the
third quarter and first nine months of 2000.

                                      7

<PAGE>

                                  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.

                                          LEXAR MEDIA, INC.

                                                  /s/ MICHAEL J. PEREZ
                                          _____________________________________
                                                    Michael J. Perez
                                           Chief Financial Officer (Principal
                                             Financial Officer and Principal
                                                   Accounting Officer)

Date: December 21, 2001

                                        8