<PAGE>   1
================================================================================

                UNITED STATES 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 September 30, 1998

                                       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: 000-27586


                           HMT TECHNOLOGY CORPORATION
             (EXACT NAME OF REGISTRANT AS SPECIFIED IN ITS CHARTER)
<TABLE>
<S>                                      <C>
            DELAWARE                                  94-3084354
(STATE OR OTHER JURISDICTION OF          (I.R.S. EMPLOYER IDENTIFICATION NUMBER)
 INCORPORATION OR ORGANIZATION)        
</TABLE>
                       1055 PAGE AVENUE, FREMONT, CA 94538
               (ADDRESS OF PRINCIPAL EXECUTIVE OFFICES) (ZIP CODE)

       Registrant's telephone number, including area code: (510) 490-3100

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

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 
                                            ---        ---

As of October 26, 1998, 43,682,577 shares of the registrant's common stock, par
value $0.001 per share, which is the only class of common stock of the
registrant, were outstanding.

================================================================================

<PAGE>   2

                           HMT TECHNOLOGY CORPORATION

                          QUARTERLY REPORT ON FORM 10-Q

                FOR THE QUARTERLY PERIOD ENDED SEPTEMBER 30, 1998


<TABLE>
<CAPTION>
PART I       FINANCIAL INFORMATION                                                    Page
<S>          <C>                                                                      <C>
Item 1.      Financial Statements

             Condensed Consolidated Balance Sheets at September 30, 1998
                 and March 31, 1998...................................................  3

             Condensed Consolidated Statements of Operations for the
                 three and six month periods ended September 30, 1998 and 1997........  4
             Condensed Consolidated Statements of Cash Flows for the
                 six months ended September 30, 1998 and 1997.........................  5

             Notes to Condensed Consolidated Financial Statements.....................  6

Item 2.      Management's Discussion and Analysis of Consolidated Financial
                 Condition and Results of Operations.................................   7


PART II      OTHER INFORMATION

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

             Signatures..............................................................  12

</TABLE>

                                       2

<PAGE>   3

PART I.  FINANCIAL INFORMATION

Item 1.  Financial Statements

                           HMT TECHNOLOGY CORPORATION

                      CONDENSED CONSOLIDATED BALANCE SHEETS
                          (Dollar amounts in thousands)

<TABLE>
<CAPTION>
                                                                          SEPTEMBER 30,      MARCH 31,
                                                                              1998             1998
                                                                              ----             ----
                                       ASSETS                             (Unaudited)
<S>                                                                        <C>               <C>
 Current assets:
   Cash and cash equivalents.............................................   $27,026          $24,985
   Receivables, net......................................................    53,767           70,016
   Inventories...........................................................    28,282           18,400
   Deposits, prepaid expenses and other assets...........................       875              629
   Deferred income taxes.................................................    12,249           12,249
                                                                           --------         --------
           Total current assets..........................................   122,199          126,923

 Property, plant and equipment, net......................................   347,064          343,856
 Other assets............................................................     6,697            7,444
                                                                           --------         --------
           Total assets..................................................  $475,960         $478,223
                                                                           ========         ========

                      LIABILITIES AND STOCKHOLDERS' EQUITY
 Current liabilities:
   Accounts payable......................................................   $22,027          $27,301
   Accrued liabilities...................................................    10,978            8,270
   Obligations under capital leases -- current portion...................       567            2,653
                                                                           --------         --------
           Total current liabilities.....................................    33,572           38,224

 Long-term liabilities...................................................     7,331            7,984
 Convertible subordinated promissory notes...............................   230,000          230,000
 Obligations under capital leases, net of current portion................       266              555
 Deferred tax liability, long-term.......................................    19,008           19,008
                                                                           --------         --------
           Total liabilities.............................................   290,177          295,771


 Common Stock............................................................        44               43
 Additional paid-in capital..............................................   110,896          109,164
 Retained earnings ......................................................   151,492          149,894
 Distribution in excess of basis.........................................   (76,649)
                                                                           --------         --------
                                                                                             (76,649)
      Total stockholders' equity.........................................   185,783          182,452
                                                                           --------         --------
           Total liabilities and stockholders' equity....................  $475,960         $478,223
                                                                           ========         ========

</TABLE>
                             See accompanying notes

                                       3

<PAGE>   4

                           HMT TECHNOLOGY CORPORATION

                 CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS
                      (In thousands, except per share data)

<TABLE>
<CAPTION>
                                                            THREE MONTHS ENDED         SIX MONTHS ENDED
                                                               SEPTEMBER 30,             SEPTEMBER 30,
                                                          ---------------------     -----------------------
                                                            1998        1997          1998          1997
                                                               (Unaudited)                (Unaudited)
<S>                                                       <C>          <C>          <C>           <C>
Net sales...............................................   $56,999     $90,446      $113,764      $167,283
Cost of sales...........................................    48,953      55,752        96,392       103,229
                                                           -------     -------      --------      --------
  Gross profit...........................................    8,046      34,694        17,372        64,054
Operating expenses:
  Research and development...............................    2,382       2,280         4,817         4,182
  Selling, general and administrative....................    2,214       3,293         4,878         7,110
                                                           -------     -------      --------      --------
     Total operating expenses............................    4,596       5,573         9,695        11,292
                                                           -------     -------      --------      --------
          Operating income...............................    3,450      29,123         7,677        52,762
Interest expense and other, net..........................    2,729       1,887         5,396         3,572
                                                           -------     -------      --------      --------
Income before income tax provision........................     721      27,235         2,281        49,190
Income tax provision, net.................................     216       8,171           684        14,757
                                                           -------     -------      --------      --------
     Net income...........................................    $505     $19,064        $1,597       $34,433
Net income available for common
 stockholders per share
     Basic..............................................     $0.01       $0.46         $0.04         $0.83
                                                           =======     =======      ========      ========
     Diluted.............................................    $0.01       $0.38         $0.04         $0.69
                                                           =======     =======      ========      ========
Shares used in computing per share amounts
     Basic..............................................    43,570      41,832        43,493        41,484
                                                           =======     =======      ========      ========
     Diluted............................................    43,570      54,482        43,493        54,145
                                                           =======     =======      ========      ========
</TABLE>

                                       4

<PAGE>   5

                           HMT TECHNOLOGY CORPORATION

                 CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS
                                 (In thousands)

<TABLE>
<CAPTION>
                                                                        SIX MONTHS ENDED
                                                                          SEPTEMBER  30,
                                                                       1998          1997
                                                                  --------------------------
                                                                          (UNAUDITED)
<S>                                                                 <C>           <C>
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income...................................................       $  1,597      $ 34,433
   Adjustments to reconcile net income to net
      cash used in operations:
      Depreciation and amortization...........................        26,992        17,696


      Changes in operating assets and liabilities:
       Receivables............................................        16,894       (15,585)
       Inventories............................................        (9,882)       (2,481)
       Deposits, prepaid expenses and other assets............          (246)         (406)
       Accounts payable.......................................        (5,275)      (10,865)
       Accrued liabilities....................................         2,708        12,915
       Long term liabilities..................................          (653)        5,053
                                                                     --------      --------
             Net cash provided by operating activities.               32,135        40,730
                                                                     --------      --------

CASH FLOWS FROM INVESTING ACTIVITIES:
   Expenditures for property, plant and equipment.............       (30,215)      (70,639)
   Decrease in other assets...................................           762           370
                                                                     --------      --------
             Net cash used in investing activities............       (29,453)      (70,269)
                                                                     --------      --------

CASH FLOWS FROM FINANCING ACTIVITIES:
   Principal payments on obligations under capital
      leases..................................................        (2,375)       (1,610)
   Proceeds from issuance of Common Stock.....................         1,734        14,551
                                                                     --------      --------
             Net cash provided by financing activities.                 (641)       12,941
                                                                     --------      --------
   Net increase (decrease) in cash and cash
    equivalents...............................................         2,041       (16,598)
   Cash and cash equivalents at beginning of period...........        24,985        55,058
                                                                     --------      --------
   Cash and cash equivalents at end of period.................      $ 27,026      $ 38,460
                                                                     ========      ========
</TABLE>

                             See accompanying notes

                                       5

<PAGE>   6

                           HMT TECHNOLOGY CORPORATION

              NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS

1.   SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

     Basis of Presentation

     The accompanying consolidated financial statements have been prepared by
the Company without audit in accordance with generally accepted accounting
principles for interim financial information and pursuant to rules and
regulations of the Securities and Exchange Commission. In the opinion of
management, all adjustments (consisting only of normal recurring adjustments)
considered necessary for a fair representation have been included. These
financial statements should be read in conjunction with the Company's
consolidated financial statements and notes thereto contained in the Company's
Annual Report on Form 10-K for the fiscal year ended March 31, 1998.

     Operating results for the quarter ended September 30, 1998 may not
necessarily be indicative of the results to be expected for any other interim
period or for the full year.

     Fiscal Year

     The Company uses a 52-week fiscal year ending on March 31 and thirteen- to
fourteen-week quarters that end on the Sunday closest to the calendar quarter
end.

     Inventories

     Inventories are stated at the lower of cost or market, and are reported net
of reserves. Cost is determined using the first-in, first-out basis.

<TABLE>
<CAPTION>
                                            SEPTEMBER 30,     MARCH 31,
                                               1998             1998
                                            -------------     ---------
                                                  (IN THOUSANDS)
<S>                                          <C>              <C>
Raw materials............................    $ 6,531          $ 7,498
Work-in-process..........................      2,696            6,024
Finished goods...........................     19,055            4,878
                                             -------          -------
                                             $28,282          $18,400
</TABLE>

Recent Accounting Pronouncements

     In June 1997, the Financial Accounting Standards Board issued Statement of
Financial Accounting Standards No. 130 ("SFAS No. 130"), "Reporting
Comprehensive Income," which will require the reporting of additional financial
information in a complete set of financial statements. SFAS No. 130 is effective
for fiscal years beginning after December 15, 1997 and will require earlier
periods to be restated to reflect application of the provisions of SFAS No. 130.
The Company believes that the adoption of SFAS 130 will have an immaterial
effect on the financial statements.

     In June 1997, the Financial Accounting Standards Board issued Statement of
Financial Accounting Standards No. 131 ("SFAS No. 131"), "Disclosures About
Segments of an Enterprise and Related

                                       6

<PAGE>   7

Information," which specifies disclosure requirements for segment reporting.
SFAS No. 131 supersedes SFAS No. 14 and SFAS No. 18 and is effective for fiscal
years beginning after December 15, 1997, and requires earlier years to be
restated if practicable. The Company believes that it operates in one segment
for purposes of SFAS 131.


SUBSEQUENT EVENTS

     On October 20, 1998, the Company announced it had implemented a reduction
in force of approximately 300 employees, and that it would take out of service
some of its under utilized production equipment and facilities. As a result, the
Company expects to incur a one-time charge to earnings of $15 to $25 million
(before taxes) in the Company's financial statements for the quarter ending
December 31, 1998.

     Effective November 2, 1998, the Company replaced its existing $100 Million
revolving credit facility with a new $50 million revolving credit facility. The
new facility expires November 2, 2000.

     On November 2, 1998, SyQuest Technology Inc. ("SyQuest"), a customer,
announced in a Form 8-K filed with the U.S. Securities and Exchange Commission
that effective November 2, 1998, it had suspended operations and is considering
alternatives, including filing of a Chapter 11 petition under the U.S.
Bankruptcy Code. On September 30, 1998 in a Form 8-K, SyQuest disclosed that it
was not in compliance with the financial covenants required by its loan
agreement with its asset-based lender. The asset based lender waived the default
and reduced the Company's credit line. As disclosed in the Form 8-K, SyQuest is
seeking additional financing from other sources. As of September 30, 1998, the
Company has approximately $4.4 million in accounts receivable due from SyQuest.
Management is currently reviewing the condition and prospects of SyQuest and
will closely monitor the status of these accounts receivables. While management
believes that, at September 30, 1998, the Company's allowance for doubtful
accounts was adequate, the ultimate collectibility of the SyQuest receivable is
dependent upon SyQuest's ability to raise additional capital. If management
determines, after further review or based on further developments at SyQuest,
that these accounts receivable are not likely to be collected, the Company will
need to take a charge for additional reserves to address the matter. 

                                       7

<PAGE>   8



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

     This discussion contains forward-looking statements, which are subject to
certain risks and uncertainties, including without limitation those described
below in the Company's Annual Report on Form 10-K, which has been filed with the
Securities and Exchange Commission. Actual results may differ materially from
the results discussed in the forward-looking statements.

OVERVIEW

     HMT Technology Corporation (the "Company") is an independent supplier of
high-performance thin film disks for high-end, high-capacity, and removable hard
disk drives, which in turn are used in PCs, network servers and work-stations.

     The Company derives substantially all of its sales from the sale of thin
film disks to a small number of customers. Loss of or a reduction in orders from
one or more of the Company's customers could result in a substantial reduction
in net sales. Because many of the Company's expense levels are based, in part,
on its expectations as to future revenues, decreases in net sales may result in
a disproportionately greater negative impact on operating results. Due to the
rapid technological change and frequent development of new disk drive products,
it is common in the industry for the relative mix of customers and products to
change rapidly, even from quarter to quarter. At any one time the Company
typically supplies disks in volume for fewer than twelve disk drive products.

RESULTS OF OPERATIONS

NET SALES THREE MONTHS ENDED SEPTEMBER 30, 1997 AND 1998. Net sales for the
three months ended September 30, 1998 were $57.0 million, down 37.0% from the
$90.4 million reported in the three months ended September 30, 1997. For the
first six months of fiscal 1999 net sales of $113.8 million were $53.5 million,
or 32.0% lower than the same period in fiscal 1998. Unit sales volume decreased
29.2% during the three months ended September 30, 1998, while average selling
prices declined 11.0%, compared to the three months ended September 30, 1997.
The decrease in unit sales volume during the three months ended September 30,
1998 was attributable to continuing weakened industry demand as disk drive
manufacturers reduced drive production and media inventory levels in response to
excess supply in many disk drive market segments. The excess media supply also
heightened price competition among independent media suppliers, causing the
decline in average selling prices. Future revenue will depend largely upon
customer demand, unit shipments and production volumes.

     During the three months ended September 30, 1998 and 1997, four customers
individually accounted for at least ten percent of consolidated net sales. The
Company expects that it will continue to derive a substantial portion of its
sales from a relatively small number of customers, although the identity of such
customers may change from period to period.

     Gross Profit. Gross margin was 14.1% of net sales for the three months
ended September 30, 1998, compared with 38.4% for the three months ended
September 30, 1997. The decline in gross margin during the three months ended
September 30, 1998 was a result of higher unit production costs and the decline
in average selling prices versus the comparable period in fiscal 1998. Unit
production costs rose as fixed costs were absorbed over lower unit production
volumes. Production volumes decreased 23% in the second quarter of fiscal 1999,
compared with the second quarter of fiscal 1998. The increase in unit production
cost, caused by lower production volumes was partially offset by reduced
salaries, as the Company responded to lower demand by reducing work hours and
eliminating bonuses for all of the Company's personnel.

     Research and Development. Research and development expenses increased
$102,000 in the three months ended September 30, 1998, compared to the same
period in 1997. Research and development


                                       8

<PAGE>   9

expenses increased primarily due to an increase in headcount related to the
Company's new product introductions and expanded research efforts to support the
Company's overall capacity expansion.

     Selling, General and Administrative. Selling, general and administrative
expenses decreased $1.1 million in the three months ended September 30, 1998,
compared to the same period in the prior fiscal year. The decrease in selling,
general and administrative expenses was primarily a result of lower headcount
and reduced salaries as the Company responded to lower demand by reducing work
hours and eliminating bonuses. The Company anticipates that operating expenses
will fluctuate in absolute dollars and as a percentage of net sales as headcount
is modified to support new product introductions and levels of production volume
and unit shipments.

     Interest Expense, Net. Net interest expense increased $842,000 during the
three months ended September 30, 1998, compared to the same period in fiscal
1998. The increase in interest expense, net was primarily a result of a decrease
in interest income (as the Company's average cash balances declined) and
capitalized interest versus the comparable period in the prior year.

     Provision for Income Taxes. For the three months ended September 30, 1998
and 1997, the Company recorded income taxes at its estimated annual effective
tax rate of 30%.

     The Company's operating results historically have been, and may continue to
be, subject to significant quarterly and annual fluctuations. As a result, the
Company's operating results in any quarter may not be indicative of its future
performance. Factors affecting operating results include: market acceptance of
new products; timing of significant orders; changes in pricing by the Company or
its competitors; timing of product announcements by the Company, its customers
or its competitors; order cancellations, modifications and quantity adjustments
and shipment rescheduling; changes in product mix; manufacturing yields; the
level of utilization of the Company's production capacity; increases in
production and engineering costs associated with initial manufacture of new
products; and changes in the cost of or limitations on the availability of
materials. The impact of these and other factors on the Company's revenues and
operating results in any future period cannot be forecasted with certainty. The
Company's expense levels are based, in part, on its expectations as to future
revenues. Because the Company's sales are generally made pursuant to purchase
orders that are subject to cancellation, modification, quantity reduction or
rescheduling on short notice and without significant penalties, the Company's
backlog as of any particular date may not be indicative of sales for any future
period, and such changes could cause the Company's net sales to fall below
expected levels. If revenue levels are below expectations, operating results are
likely to be materially adversely effected. Net income, if any, and gross
margins may be disproportionately affected by a reduction in net sales because a
proportionately smaller amount of the Company's expenses varies with its
revenues.

LIQUIDITY AND CAPITAL RESOURCES

     Cash and cash equivalents increased by $2.0 million to $27.0 million at
September 30, 1998 from March 31, 1998. Cash flows from operations were $32.1
million for the six-month period ended September 30, 1998 as compared to $40.7
million in the comparable period of 1997. Cash generated during the six months
ended September 30, 1998 reflected net income plus depreciation and
amortization, a decrease in receivables and accounts payable, as well as an
increase in accrued liabilities, offset by an increase in inventories. Decreased
sales and lower margins contributed to the decline in positive cash flow
provided by operations during the six months ended September 30, 1998 as
compared to the six months ended September 30, 1997.

     The Company invested $30.2 million and $70.6 million in property, plant and
equipment during the six months ended September 30, 1998 and 1997, respectively.
The Company currently expects to spend approximately $60 million over the next
twelve months on property, plant & equipment.

     Cash used by financing activities for the first six months of fiscal 1999
reflected $2.4 million in principal payments on capital leases, offset by $1.7
million in cash received for employee stock purchases.

                                       9

<PAGE>   10

     As of September 30, 1998, the Company's principal sources of liquidity
consisted of cash, cash equivalents and short-term investments, as well as the
full balance of the $100 million revolving credit facility.

     The Company believes existing cash balances, cash generated from
operations, and funds available under its credit facilities, will provide
adequate cash to fund its operations and anticipated capital expenditures at
least through September 30, 1999. Should improved market conditions result in a
need for a substantial expansion in the Company's manufacturing capacity, the
Company may need to obtain additional sources of financing. There can be no
assurance that the Company will be able to obtain any needed alternative sources
of financing on favorable terms, if at all, at such time or times as the Company
may require such capital.

YEAR 2000 COMPLIANCE

     The Company has reviewed both its internal computer systems and its
products that could be affected by the "Year 2000" issue and has identified some
systems that will be affected. In the ordinary course of replacing computer
equipment and software, the Company attempts to obtain replacements that are
Year 2000 compliant. Utilizing both internal and external resources to identify
and assess needed Year 2000 remediation, the Company currently anticipates that
its internal Year 2000 identification, assessment, remediation and testing
efforts, which began in October 1997, will be completed on or about June 30,
1999, and that such efforts will be completed prior to any currently anticipated
impact on its internal computer equipment and software.

     The Company presently believes, with modification to existing software and
conversion to new software, the "Year 2000" issues relating to internal computer
systems and products will not cause significant operational problems or computer
problems. Furthermore, the cost of implementing these solutions is not
anticipated to be material to the financial position or results of operations.
However, if such modifications and conversions are not made, or not completed,
the "Year 2000" issue could have a material adverse impact on the operations of
the Company. Furthermore, the costs of such conversions and updates are based on
management's best estimates, which are derived utilizing numerous assumptions of
future events including such things as, but not limited to, the availability and
cost of personnel trained in this area, the ability to locate and correct all
relevant computer code and similar uncertainties. There can be no assurance that
the Company will be able to upgrade any or all of its, major systems or, once
upgraded, that the systems will be Year 2000 compliant. Should the Company fail
to upgrade such systems in a timely manner, or should those upgrades fail to be
Year 2000 compliant, the Company may be unable to conduct business or
manufacture its products, which could cause a material adverse effect on the
Company's results of operations.

     The Company has initiated formal communications with all of its significant
suppliers and large customers during fiscal 1999 to determine the extent to
which the Company is vulnerable to those third parties failure to remediate
their own "Year 2000" issues. There can be no guarantee that the systems or
products of other companies or significant suppliers will be converted. A
failure to convert by another company, or a conversion that is incompatible with
the Company's systems may have a material adverse impact on the Company. As of
September 15, 1998, the Company had received responses from approximately 70% of
such third parties, and 95% of the companies that have responded have provided
written assurances that they expect to address all their significant Year 2000
issues on a timely basis.

     The Company's suppliers and customers may be adversely affected by their
respective failure to address the Year 2000 problem. Should any of the Company's
suppliers encounter Year 2000 problems that cause them to delay manufacturing or
shipments of key components, the Company may be forced to delay or cancel
shipments of its products, which would have a material adverse effect on the
Company's results of operations. Additionally, any inability of customers to
become Year 2000 compliant which would cause them to delay or cancel substantial
purchase orders or delivery of products would also have a material adverse
effect on the Company's results of operations. The Company is currently working
with its suppliers, to address their Year 2000 compliance in a timely manner.
The Company anticipates completion of this effort by June of 1999; however,
there can be no assurance that any such effort will be successful.

                                       10

<PAGE>   11

     Currently, the Company does not have a contingency plan in place should the
Company be unsuccessful in its efforts to become Year 2000 compliant. However,
the Company intends to create such a contingency plan by July of 1999.

     The following table outlines the targets for the Company's Year 2000
efforts, however, there can be no assurance that these targets will be met.

<TABLE>
<CAPTION>

ITEM                               % Complete         Due
<S>                                <C>                <C>
Inventory Internal Systems              100%          3/98
Inventory Vendor Systems                100%          3/98
Vendor Response                          70%          1/99
Remediate Internal Systems               70%          6/99
Vendor Remediation                       50%          6/99
Contingency Plan                          0%          6/99
</TABLE>


                                       11

<PAGE>   12

Part II   Other Information

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

(a)  The Annual Meeting of Stockholders was held on July 20, 1998.

(b)  The following individuals, each of whom served as directors of the Company
prior to the annual meeting, were elected to serve as Directors until the next
annual meeting:

<TABLE>
<CAPTION>
                          Total Vote For       Total Vote Withheld
                           Each Director        From Each Director
                          --------------       -------------------
<S>                       <C>                  <C>
Ronald L. Schauer           37,691,353               145,048
Donald P. Beadle            37,684,419               151,982
Bruce C. Edwards            37,694,516               141,885
Walter G. Kortschak         37,694,466               141,935
Richard S. Love             37,686,529               149,872
Harry G. Van Wickle         37,684,851               151,550
</TABLE>

(c)  The Stockholders voted to ratify the amendment to the Company's 1996 Equity
     Incentive Plan, to increase the aggregate number of shares of Common Stock
     authorized for issuance under such plan by 2,500,000 shares.

     1.        A proposal to approve the Company's 1996 Equity Incentive Plan, 
          as amended, to increase the aggregate number of shares of Common Stock
          authorized for issuance under such plan by 2,500,000 share: 19,968,616
          shares were voted in favor of the proposal, 8,090,423 shares were
          voted against the proposal, 577,904 shares abstained and 9,199,458
          shares were broker non-votes.

     2.       The ratification of the selection of PricewaterhouseCoopers LLP as
          the Company's Independent Auditors for the fiscal year ended March 31,
          1999: 37,794,187 shares were voted in favor of the proposal, 16,048
          shares were voted against the proposal, and 26,166 shares abstained.

Item 5.   Other Information

          Pursuant to the Company's bylaws, stockholders who wish to bring
          matters or propose nominees for director at the Company's 1999 annual
          meeting of stockholders must provide specified information to the
          Company between April 20, 1999 and May 20, 1999 (unless such matters
          are included in the Company's proxy statement pursuant to Rule 14a-8
          under the Securities Exchange Act of 1934, as amended).

Item 6.   Exhibits and Reports on Form 8-K

(a)   Reports on Form 8-K:

     During the quarter ended September 30, 1998, the Company did not file any
reports on Form 8-K.

               During the quarter ended September 30, 1998, there were no
          reports on Form 8-K filed by the Company.

                                       12

<PAGE>   13

                                   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.

                   
                           HMT TECHNOLOGY CORPORATION
                                  (Registrant)

<TABLE>
<S>                                 <C>
Date:    November 11, 1998          BY:  /s/ Peter S. Norris
     ---------------------             ---------------------

                                         Peter S. Norris
                                         Vice President and
                                         Chief Financial Officer


Date:    November 11, 1998          BY:  /s/ Ronald L. Schauer
     ---------------------             -----------------------

                                         Ronald L. Schauer
                                         President and
                                         Chief Executive Officer
</TABLE>

                                       13

<PAGE>   14

EXHIBIT INDEX

(a)  Exhibits:

<TABLE>
Exhibit No.
-----------
<S>      <C>
11.1     Statement Regarding Computation of Net Income Per Share.
27.1     Financial Data Schedule.
</TABLE>

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