<PAGE>   1
                             SECURITIES AND EXCHANGE
                                   COMMISSION

                             Washington, D.C. 20549

                                   ---------

                                    FORM 10-Q

                   Quarterly Report Under Section 13 or 15(d)
                     of the Securities Exchange Act of 1934

                                   ---------


For Quarter Ended March 31, 2001                   Commission File number 1-5341
                  --------------                                          ------


                                ELCOR CORPORATION
             ------------------------------------------------------
             (Exact name of Registrant as specified in its charter)


         DELAWARE                                               75-1217920
-------------------------------                              -------------------
(State or other jurisdiction of                               (I.R.S. Employer
 incorporation or organization)                              Identification No.)


            14643 DALLAS PARKWAY
SUITE 1000, WELLINGTON CENTRE, DALLAS, TEXAS                          75240-8871
--------------------------------------------                          ----------
 (Address of principal executive offices)                             (Zip Code)

Registrant's telephone number, including area code                (972) 851-0500
                                                                  --------------


         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 close of business on May 1, 2001, Registrant had outstanding
19,229,119 shares of Common Stock, Par Value $1 per Share.


<PAGE>   2



PART I.  FINANCIAL INFORMATION

ITEM 1.  Financial Statements

                                ELCOR CORPORATION
                           CONSOLIDATED BALANCE SHEET
                           (Unaudited, $ in thousands)

<TABLE>
<CAPTION>
                                                                       March 31,    June 30,
ASSETS                                                                    2001        2000
------                                                                 ---------    ---------
<S>                                                                    <C>          <C>
CURRENT ASSETS
Cash and cash equivalents                                              $   1,444    $   4,702
Trade receivables, less allowance of $958 and $963                        63,333       71,712
Inventories -
         Finished goods                                                   47,656       29,249
         Work-in-process                                                     113          259
         Raw materials                                                    12,985       11,457
                                                                       ---------    ---------
                  Total inventories                                       60,754       40,965
                                                                       ---------    ---------

Prepaid expenses and other                                                 8,191        4,312
Deferred income taxes                                                      3,032        2,822
                                                                       ---------    ---------
                  Total current assets                                   136,754      124,513
                                                                       ---------    ---------

PROPERTY, PLANT AND EQUIPMENT, AT COST                                   311,359      279,028
         Less - accumulated depreciation                                 (93,961)     (83,924)
                                                                       ---------    ---------
                  Property, plant and equipment, net                     217,398      195,104
                                                                       ---------    ---------

OTHER ASSETS                                                               2,838        2,957
                                                                       ---------    ---------
                                                                       $ 356,990    $ 322,574
                                                                       =========    =========

LIABILITIES AND SHAREHOLDERS' EQUITY
------------------------------------

CURRENT LIABILITIES
Accounts payable                                                       $  31,481    $  36,034
Accrued liabilities                                                       10,530       12,253
                                                                       ---------    ---------
                  Total current liabilities                               42,011       48,287
                                                                       ---------    ---------

LONG-TERM DEBT                                                           130,700       91,300
DEFERRED INCOME TAXES                                                     23,259       21,083

SHAREHOLDERS' EQUITY -
         Common stock, $1 par                                             19,988       19,988
         Paid-in-capital                                                  58,228       58,480
         Retained earnings                                                94,630       90,641
                                                                       ---------    ---------
                                                                         172,846      169,109
         Less - Treasury stock (759,910 and 436,395 shares, at cost)     (11,826)      (7,205)
                                                                       ---------    ---------
                  Total shareholders' equity                             161,020      161,904
                                                                       ---------    ---------
                                                                       $ 356,990    $ 322,574
                                                                       =========    =========
</TABLE>


See accompanying notes to consolidated financial statements


                                       1
<PAGE>   3

                                ELCOR CORPORATION
                      CONSOLIDATED STATEMENT OF OPERATIONS
                           (Unaudited, $ in thousands
                             except per share data)


<TABLE>
<CAPTION>
                                               Three Months Ended        Nine Months Ended
                                                    March 31,                March 31,
                                             ----------------------    ----------------------
                                                2001        2000         2001         2000
                                             ---------    ---------    ---------    ---------
<S>                                          <C>          <C>          <C>          <C>
SALES                                        $  76,063    $  90,448    $ 230,884    $ 267,973
                                             ---------    ---------    ---------    ---------

COST AND EXPENSES
       Cost of sales                            61,993       70,607      182,237      201,023
       Selling, general and administrative      11,665       10,002       35,652       29,352
                                             ---------    ---------    ---------    ---------
INCOME FROM OPERATIONS                           2,405        9,839       12,995       37,598
                                             ---------    ---------    ---------    ---------

OTHER INCOME (EXPENSE)
       Gain from involuntary conversion             --          403           --        1,292
       Interest expense, net                      (903)        (239)      (2,031)        (760)
                                             ---------    ---------    ---------    ---------

INCOME BEFORE INCOME TAXES                       1,502       10,003       10,964       38,130
       Provision for income taxes                  565        3,792        4,078       14,439
                                             ---------    ---------    ---------    ---------
NET INCOME                                   $     937    $   6,211    $   6,886    $  23,691
                                             =========    =========    =========    =========

NET INCOME PER SHARE-BASIC                   $     .05    $     .32    $     .36    $    1.21
                                             =========    =========    =========    =========

NET INCOME PER SHARE-DILUTED                 $     .05    $     .31    $     .35    $    1.18
                                             =========    =========    =========    =========

DIVIDENDS PER COMMON SHARE                   $     .05    $     .05    $     .15    $     .15
                                             =========    =========    =========    =========
</TABLE>


See accompanying notes to consolidated financial statements.


                                       2
<PAGE>   4


                                ELCOR CORPORATION
                      CONSOLIDATED STATEMENT OF CASH FLOWS
                           (Unaudited, $ in thousands)

<TABLE>
<CAPTION>
                                                                           Nine Months Ended
                                                                               March 31,
                                                                         --------------------
                                                                           2001        2000
                                                                         --------    --------
<S>                                                                      <C>         <C>
CASH FLOWS FROM OPERATING ACTIVITIES

         Net income                                                      $  6,886    $ 23,691
         Adjustments to reconcile net income
            to net cash provided by operating activities:

                  Depreciation and amortization                            10,283       7,930
                  Deferred income taxes                                     1,966       1,335
                  Gain from involuntary conversion                             --      (1,292)
                  Changes in assets and liabilities:
                     Trade receivables                                      8,379      (5,781)
                     Inventories                                          (19,789)     (9,217)
                     Prepaid expenses and other                            (3,879)      4,398
                     Accounts payable and accrued liabilities              (6,276)      3,270
                                                                         --------    --------

                  Net cash provided by (used for) operating activities     (2,430)     24,334
                                                                         --------    --------

CASH FLOWS FROM INVESTING ACTIVITIES

         Additions to property, plant and equipment                       (32,555)    (49,816)
         Insurance proceeds from involuntary conversion                        --       2,310
         Other                                                                 97         504
                                                                         --------    --------

                  Net cash used for investing activities                  (32,458)    (47,002)
                                                                         --------    --------

CASH FLOWS FROM FINANCING ACTIVITIES

         Long-term borrowings, net                                         39,400      25,700
         Dividends on common stock                                         (2,897)     (2,936)
         Treasury stock transactions and other, net                        (4,873)        570
                                                                         --------    --------

                  Net cash provided by financing activities                31,630      23,334
                                                                         --------    --------

NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS                       (3,258)        666

CASH AND CASH EQUIVALENTS AT BEGINNING OF YEAR                              4,702       4,186
                                                                         --------    --------

CASH AND CASH EQUIVALENTS AT END OF PERIOD                               $  1,444    $  4,852
                                                                         ========    ========
</TABLE>


See accompanying notes to consolidated financial statements.


                                       3
<PAGE>   5


                                ELCOR CORPORATION
                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                                   (Unaudited)

1.       The attached condensed consolidated financial statements have been
         prepared pursuant to the rules and regulations of the Securities and
         Exchange Commission. As a result, certain information and footnote
         disclosures normally included in financial statements prepared in
         accordance with generally accepted accounting principles have been
         condensed or omitted. The company believes that the disclosures
         included herein are adequate to make the information presented not
         misleading. These condensed consolidated financial statements should be
         read in conjunction with the consolidated financial statements and
         related notes included in the company's fiscal 2000 Annual Report on
         Form 10-K. The unaudited financial information contained herein has
         been prepared in conformity with generally accepted accounting
         principles on a consistent basis and does reflect all adjustments which
         are, in the opinion of management, necessary for a fair presentation of
         the results of operations for the three-month and nine-month periods
         ending March 31, 2001 and 2000, but are, however, subject to year-end
         audit by the company's independent auditors. Because of seasonal,
         weather-related conditions in some of the company's market areas, sales
         can vary at times, and results of any one quarter or other interim
         reporting period should not necessarily be considered as indicative of
         results for a full fiscal year.

2.       In accordance with the requirements of FASB SFAS No. 131, the company
         is segregated into the following segments: Roofing Products,
         Electronics Manufacturing Services and Industrial Products. The Roofing
         Products segment consists of the various operating subsidiaries of Elk
         Corporation of Dallas (collectively Elk). These companies manufacture
         and sell premium laminated fiberglass asphalt residential and accessory
         roofing products, together with nonwoven mats used in manufacturing
         asphalt roofing products and various industrial applications.

         The Electronics Manufacturing Services segment consists of the various
         operating subsidiaries of Cybershield, Inc. (collectively Cybershield).
         These companies are engaged in the shielding of plastic electronics
         enclosures by the use of electroless metallic chemicals, vacuum
         metalization, robotic spray metallic paints and conductive dispense
         gaskets, application of pad print and/or decorative paint finishes,
         installation of antenna components, light tubes, battery connections,
         inserts, subassembly operations and other value added services for the
         telecommunications, computer and electronic equipment industries. Due
         to the increasing materiality of the Electronics Manufacturing Services
         business to the company, its operations have been segregated into a
         separate segment as of June 30, 2000. These operations were previously
         included in the Industrial Products segment.

         The Industrial Products segment is comprised of: (1) surface finishing
         of original equipment and remanufactured reciprocating diesel engine
         components used in the railroad and marine transportation industries;
         and (2) technology licensing and consulting services for the natural
         gas processing industry.


                                       4
<PAGE>   6


         Financial information by company segment is summarized as follows (in
thousands):

<TABLE>
<CAPTION>
                                      Three Months Ended         Nine Months Ended
                                           March 31,                  March 31,
                                     ----------------------    ----------------------
                                        2001        2000         2001         2000
                                     ---------    ---------    ---------    ---------
<S>                                  <C>          <C>          <C>          <C>
SALES
Roofing products                     $  65,693    $  80,479    $ 197,534    $ 232,248
Electronics manufacturing services       6,820        7,743       23,556       26,752
Industrial products                      3,520        2,186        9,705        8,844
Corporate and eliminations                  30           40           89          129
                                     ---------    ---------    ---------    ---------
                                     $  76,063    $  90,448    $ 230,884    $ 267,973
                                     =========    =========    =========    =========
OPERATING PROFIT (LOSS)
Roofing products                     $   3,908    $  13,271    $  18,270    $  40,866
Electronics manufacturing services         556        1,069        2,172        4,681
Industrial products                       (171)      (2,430)      (1,119)      (3,106)
Corporate and other                     (1,888)      (2,071)      (6,328)      (4,843)
                                     ---------    ---------    ---------    ---------
                                         2,405        9,839       12,995       37,598
Gain from involuntary conversion            --          403           --        1,292
Interest expense, net                     (903)        (239)      (2,031)        (760)
                                     ---------    ---------    ---------    ---------
Income before income taxes           $   1,502    $  10,003    $  10,964    $  38,130
                                     =========    =========    =========    =========
IDENTIFIABLE ASSETS
Roofing products                     $ 293,886    $ 251,018    $ 293,886    $ 251,018
Electronics manufacturing services      32,270       25,135       32,270       25,135
Industrial products                     10,421        6,538       10,421        6,538
Corporate                               20,413       21,381       20,413       21,381
                                     ---------    ---------    ---------    ---------
                                     $ 356,990    $ 304,072    $ 356,990    $ 304,072
                                     =========    =========    =========    =========
DEPRECIATION AND AMORTIZATION
Roofing products                     $   2,380    $   2,122    $   6,776    $   6,333
Electronics manufacturing services         363          428        1,153        1,218
Industrial products                        148           88          298          265
Corporate                                  693           38        2,056          114
                                     ---------    ---------    ---------    ---------
                                     $   3,584    $   2,676    $  10,283    $   7,930
                                     =========    =========    =========    =========
CAPITAL EXPENDITURES
Roofing products                     $   5,904    $  16,395    $  28,136    $  41,767
Electronics manufacturing services         192          762        3,531        3,577
Industrial products                        351          690          721        1,254
Corporate                                   60          639          167        3,218
                                     ---------    ---------    ---------    ---------
                                     $   6,507    $  18,486    $  32,555    $  49,816
                                     =========    =========    =========    =========
</TABLE>


                                       5
<PAGE>   7


3.       Basic earnings per share is computed based on the average number of
         common shares outstanding. Diluted earnings per share includes
         outstanding stock options. The following table sets forth the
         computation of basic and diluted earnings per share (dollars and share
         totals, in thousands):

<TABLE>
<CAPTION>
                                    Three Months Ended   Nine Months Ended
                                        March 31,             March 31,
                                    ------------------   ------------------
                                      2001       2000      2001       2000
                                    -------    -------   -------    -------
<S>                                 <C>        <C>       <C>        <C>
Net income                          $   937    $ 6,211   $ 6,886    $23,691
                                    =======    =======   =======    =======

Denominator for basic earnings
per share - weighted average
shares outstanding                   19,220     19,603    19,353     19,565

Effect of dilutive securities:
Employee stock options                  169        599       174        520
                                    -------    -------   -------    -------

Denominator for dilutive earnings
per share - adjusted weighted
average shares and assumed
issuance of shares purchased
under incentive stock option plan
using the treasury stock method      19,389     20,202    19,527     20,085
                                    =======    =======   =======    =======

Basic earnings per share            $   .05    $   .32   $   .36    $  1.21
                                    =======    =======   =======    =======

Diluted earnings per share          $   .05    $   .31   $   .35    $  1.18
                                    =======    =======   =======    =======
</TABLE>


4.       On November 30, 2000, the company increased its revolving credit
         facility from $125,000,000 to $175,000,000 and extended its term to
         November 30, 2005. Effective March 31, 2001, the company amended the
         facility in order to make certain financial covenants less restrictive
         and agreed to collateralize the facility with certain trade receivables
         and inventories if specified financial ratios are not met beginning
         June 30, 2001. The pricing level for base rate loans, Eurodollar rate
         loans and commitment fees are determined on the company's leverage
         ratio, as defined, at each quarter end. Based on the leverage ratio at
         March 31, 2001, the base rate for borrowings, as amended, will be prime
         plus .625%, the Eurodollar borrowing rate will be LIBOR plus 2.5% and
         the commitment fee will be .5% of the average unused portion of the
         line.

         The facility, as amended, among other things, requires that the company
         maintain a specified minimum consolidated net worth, a minimum fixed
         charge coverage ratio and a maximum capitalization ratio, all based on
         defined terms. The facility also contains restrictions that limit the
         payment of cash dividends and stock repurchases based on defined
         criteria.

5.       During the second quarter of fiscal 2001, management determined that
         the useful lives of certain buildings and equipment utilized in the
         Electronics Manufacturing Services segment were longer than originally
         established. A change in accounting estimate was recognized to reflect
         this decision, resulting in an increase in pretax income of $150,000
         per fiscal quarter beginning in the quarter ended December 31, 2000.


                                       6
<PAGE>   8

ITEM 2. Management's Discussion and Analysis of Financial Condition and Results
        of Operations

RESULTS OF OPERATIONS

CHANGES IN THE THREE-MONTH PERIOD ENDED MARCH 31, 2001 COMPARED TO THE
THREE-MONTH PERIOD ENDED MARCH 31, 2000.

         During the three-month period ended March 31, 2001, net income
decreased to $937,000 compared to $6,211,000 for the same prior year period.
Sales decreased 16% to $76,063,000 in the third quarter of fiscal 2001 compared
to $90,448,000 in the same period of fiscal 2000. Decreased sales and income
were reported in the Roofing Products and Electronics Manufacturing Services
segments. However, the Industrial Products segment achieved higher sales and
much improved operating results. During the three-month period ended March 31,
2000, the company recorded $403,000 gain from involuntary conversion as a result
of insurance proceeds exceeding the book value of assets destroyed in a plant
explosion in September 1998 at its nonwoven fiberglass roofing mat plant in
Ennis, Texas. Final settlement with the company's insurance company was reached
in fiscal 2000.

         Sales for the Roofing Products segment decreased 18% to $65,693,000 for
the three months ended March 31, 2001 compared to $80,479,000 in the same prior
year quarter. The decrease in sales reflected a decline in shipments of both
laminated asphalt shingles and nonwoven fiberglass roofing mat sold to other
roofing manufacturers. Lower demand for residential asphalt roofing products in
many regions of the country resulted from weakening industry conditions. Demand
in the current year quarter was also adversely effected by heavy winter and
spring rains in many parts of the country and unusually harsh winter weather in
the Northern region of the United States.

         Operating income for the Roofing Products segment decreased 71% to
$3,908,000 for the three months ended March 31, 2001 compared to $13,271,000 in
the prior year quarter. The decrease in operating income compared to the prior
year is primarily the result of the decrease in shipments of premium laminated
fiberglass shingles and nonwoven fiberglass mats, combined with higher costs for
raw materials and higher expenses relating to the start-up of new facilities and
products. Asphalt costs, which account for about 24% of cost of goods sold for
laminated asphalt shingles, were higher in the quarter ended March 31, 2001
compared to the same quarter last year. Average selling prices for laminated
shingles were slightly lower in the current year quarter compared to the same
prior year period. Marketing and promotion costs were much higher in the current
year quarter compared to the same quarter last year in part due to Elk expanding
its distribution network in conjunction with construction of the new Myerstown,
Pennsylvania roofing plant. Sales and operating income in last year's third
quarter also included $1,700,000 of income relating to the final settlement of a
business interruption claim.

         Sales for the Electronics Manufacturing Services segment decreased 12%
to $6,820,000 in the third quarter of fiscal 2001 compared to $7,743,000 in the
same period last year. Operating income decreased 48% to $556,000 in the
three-month period ended March 31, 2001 from $1,069,000 in the same three-month
period last year. The current year's third quarter results reflect lower demand
resulting from the significant reduction in the production of telecommunications
equipment as the industry focused on reducing inventories in response to slowing
end-user demand.


                                       7
<PAGE>   9


         Sales for the Industrial Products Group increased 61% to $3,520,000 in
the three-month period ending March 31, 2001 compared to $2,186,000 in the same
prior year quarter. A $171,000 operating loss was reported in the current year
quarter compared to a $2,430,000 operating loss in the prior year quarter.
Significantly improved results were due primarily to Chromium Corporation's
turnaround after consolidating all manufacturing operations into its Cleveland,
Ohio facility. The prior year operating loss included about $1,650,000 of
nonrecurring costs to relocate equipment and other consolidation related items.
Ortloff Engineers, the company's patent licensing and engineering consulting
services business, reported operating results in the current year quarter
comparable to the same prior year quarter. However, negotiations on some new
technology licensing opportunities were substantially completed during the
quarter but definitive contracts had not been executed by quarter end.

         Overall selling, general and administrative costs (SG&A) in the
three-month period ending March 31, 2001 were 17% higher than in the same period
in the prior fiscal year. Increased costs compared to the prior year period
included higher sales and marketing costs in the Roofing Products segment and
higher depreciation at corporate relating to a new enterprise resource system.

         Net interest expense in the third quarter of fiscal 2001 was $903,000
compared to $239,000 in the same prior year period. The company capitalized
$1,298,000 of interest in the current year quarter compared to $748,000 in the
prior year quarter. Capitalized interest expense in both years primarily related
to the construction of the new Myerstown, Pennsylvania shingle plant.

CHANGES IN THE NINE-MONTH PERIOD ENDED MARCH 31, 2001 COMPARED TO THE NINE-MONTH
PERIOD ENDED MARCH 31, 2000.

         During the nine-month period ended March 31, 2001, net income decreased
to $6,886,000 from $23,691,000 in last year's period. Sales decreased 14% to
$230,884,000 in the current year period from $267,973,000 in the same prior year
period. Decreased sales and income were reported in the Roofing Products and
Electronics Manufacturing Services segments. The Industrial Products segment
reported increased sales and a much smaller operating loss for the first nine
months of fiscal 2001 compared to the same prior year period. During the
nine-month period ended March 31, 2000, the company recorded a $1,292,000 gain
from involuntary conversion as a result of payments on a property claim whereby
the company received replacement value payments in excess of the net book value
of destroyed assets on a claim that was settled in February 2000.

         Sales for the Roofing Products segment decreased 15% to $197,534,000
for the nine months ended March 31, 2001 compared to $232,248,000 in the same
period last year. During the first nine months of fiscal 2001, sales of the
company's laminated asphalt shingles and nonwoven fiberglass mat sold to other
roofing manufacturers declined in many regions of the country as a result of a
combination of factors, including overall weakened economic conditions, harsh
winter weather conditions in the Northern United States, heavy winter and spring
rains in many parts of the country, and actions by competitors in the early part
of fiscal 2001 to increase their production of laminated shingles to compensate
for lower demand for commodity shingles.

         Operating income for the Roofing Products segment decreased
significantly to $18,270,000 for the first nine months of fiscal 2001 compared
to $40,866,000 for the same period in the prior fiscal year. Average selling
prices for laminated shingles were slightly lower in the current year period
compared to the same period last year and the company incurred much higher raw
material costs, particularly asphalt and glass fiber costs, and higher expenses
relating to start-up of the new Myerstown, Pennsylvania roofing plant and
development of new products. Operating income for the nine months ended March


                                       8
<PAGE>   10


31, 2000 included $3,478,000 of income relating to a business interruption claim
that was settled in February 2000. These factors, combined with lower shipments
of roofing products, resulted in a 55% reduction in operating profit compared to
the prior year.

         Management is cautiously optimistic that the roofing business is poised
for recovery. The heavy winter and spring rains experienced in many parts of the
country and the unusually harsh winter weather experienced in the Northern
regions of the United States should result in increased roofing demand during
the summer roofing season, which will benefit both the shingle and mat
businesses. Management also believes that industry manufacturing capacity and
inventory levels have tightened as a result of a competitor's permanent closure
of three roofing plants and a reduced level of production at some other plants
this winter. Most major roofing manufacturers have recently implemented modest
price increases. Asphalt raw material prices have stabilized, and in some cases
are falling moderately. Management further believes that Elk's winter sales
program was successful and its Prestique premium laminated shingle line is well
stocked in distribution channels moving into the roofing season. Finally, the
new Myerstown plant gives Elk the production capacity to fully participate in
any market recovery and to expand Elk's product development efforts.

         Sales for the Electronics Manufacturing Services segment decreased 12%
to $23,556,000 in the nine-month period ended March 31, 2001 compared to
$26,752,000 in the same period in the prior fiscal year. Lower sales were
primarily the result of reduced demand for digital cell phone models and
infrastructure equipment served by Cybershield as the telecommunications
equipment industry focused on reducing inventories in response to slowing
end-user demand. This resulted in a significant reduction in production
requirements for new models and products. Operating income decreased 54% to
$2,172,000 in the first nine months of fiscal 2001 from $4,681,000 in the
nine-month period ended March 31, 2000. Decreased operating income is primarily
attributable to reduced sales and higher costs incurred earlier in the current
fiscal year for initial production ramp-ups on new digital wireless handset
products, which were subsequently curtailed.

         Management believes the sales growth and operating margins in the
Electronics Manufacturing Services segment will continue under pressure until
inventories in the wireless telecommunication industry are reduced to a more
appropriate level in relation to current demand. Management cannot currently
predict the duration of this correction with any degree of confidence.

         Sales for the Industrial Products segment increased 10% in the
nine-month period ended March 31, 2001 to $9,705,000 from $8,844,000 for the
same period in the prior fiscal year. An operating loss of $1,119,000 was
reported in the current year period compared to a $3,106,000 operating loss in
the prior year period. The current year included an operating loss in July 2000
that was the result of the consolidation of manufacturing operations and initial
production of products new to Chromium Corporation's Cleveland, Ohio plant.
Excluding the results for July 2000, Chromium has generated an operating profit
for each month of current year period and the outlook appears good for
continuing improvement during the remainder of fiscal 2001. The prior year
period operating loss included a significant amount of nonrecurring items
relating to the consolidation of Chromium's manufacturing operations. Excluding
these costs, Chromium's operating results were near break-even in the first nine
months of fiscal 2000. Ortloff Engineers experienced lower sales and operating
results in the first nine months of fiscal 2001 compared to the same prior year
period. However, its outlook for awards of significant licenses of the company's
leading edge patented cryogenic gas processing technology appears good in the
months ahead.


                                       9
<PAGE>   11


         Overall S,G&A costs in the nine-month period ending March 31, 2001 were
21% higher than in the same period in the prior fiscal year, primarily as a
result of higher sales and marketing costs primarily related to the new
Myerstown plant expansion in the Roofing Products segment and higher
depreciation at corporate relating to a new enterprise resource system.

         Net interest expense in the first nine months of fiscal 2001 was
$2,031,000 compared to $760,000 in the same prior year period. The company
capitalized $3,965,000 of interest in the current year period compared to
$1,532,000 of interest in the prior year period in connection with the
construction of its new Myerstown, Pennsylvania shingle plant and other major
products. Interest expense is expected to be higher for the remainder of fiscal
2001, primarily due to increased debt levels relating to the seasonally higher
levels of working capital.

FINANCIAL CONDITION

         During the first nine months of fiscal 2001, the company utilized cash
flows of $2,430,000. Overall working capital at March 31, 2001 (excluding cash
and cash equivalents) was $21,775,000 higher than at June 30, 2000. Trade
receivables were $8,379,000 lower at March 31, 2001 compared to June 30, 2000,
due to decreased product shipments. Receivables at March 31, 2001 include
amounts with extended payment terms to certain customers for products shipped
during the late winter and early spring months, with most payments generally due
during the spring. The decrease in receivables was more than offset by higher
inventories, higher prepaid expenses and lower current liabilities.

         Higher inventories of premium laminated fiberglass shingles and roofing
mats reflect increases in both units and cost per unit, as well as building an
initial base level of inventory at the new Myerstown, Pennsylvania roofing
plant. Inventory levels have been increased so as to enter the roofing season
with ample roofing inventories in order to take full advantage of a potential
rebound in the roofing market. Management intends to significantly reduce
inventories before winter by increased sales levels and/or reduced production
rates. The current ratio at March 31, 2001 was 3.2:1 compared to 2.6:1 at the
end of fiscal 2000. Historically, working capital requirements fluctuate during
the year because of seasonality in some market areas. Generally, working capital
requirements and related borrowings are higher in the spring and summer months,
and lower in the fall and winter months.

         The company used $32,458,000 for net investing activities in the first
nine months of fiscal 2001. Most expenditures were for additions to property,
plant and equipment. About $23,000,000 of capital expenditures in the first nine
months of fiscal 2001 were for construction costs relating to the new Myerstown,
Pennsylvania premium laminated fiberglass asphalt shingle plant. Construction of
this new facility has been completed, start-up is underway and limited
manufacturing operations began in the December 2000 quarter. The Myerstown plant
is expected to increase the company's overall laminated shingle capacity by
about 38%. The company currently plans to continue its expansion plan over the
next several years in accordance with its assessment of growth in market demand,
primarily by improving productivity at existing plants, developing new products
and installing production lines for new products.

         Cash flows from financing activities were $31,630,000 during the first
nine months of fiscal 2001, primarily resulting from a $39,400,000 increase in
long-term debt. Long-term debt represented almost 45% of the $291,720,000 of
invested capital (long-term debt plus shareholders' equity) at March 31, 2001.


                                       10
<PAGE>   12


         In September 1998, the company's Board of Directors authorized the
purchase of up to $10,000,000 of common shares from time to time on the open
market to be used for general corporate purposes. On August 28, 2000, the Board
of Directors authorized the repurchase of up to an additional $10,000,000 of
common stock. As of March 31, 2001, 600,590 shares with cumulative cost of
$9,366,000 had been repurchased under these authorizations.

         On November 30, 2000, the company increased its revolving credit
facility from $125,000,000 to $175,000,000 to support its capital expansion
program. Management believes that current cash and cash equivalents, projected
cash flows from operations and the increased revolving credit facility should be
sufficient during fiscal 2001 and beyond to fund its expansion plans, working
capital needs, dividends, stock repurchases and other cash requirements.

         The company's operations are subject to extensive federal, state and
local laws and regulations relating to environmental matters. Although the
company does not believe it will be required to expend amounts which will have a
material adverse effect on the company's consolidated financial position or
results of operations by reason of environmental laws and regulations, such laws
and regulations are frequently changed and could result in significantly
increased cost of compliance. Further, certain of the company's industrial
products and electronics manufacturing services operations utilize hazardous
materials in their production processes. As a result, the company incurs costs
for remediation activities off-site and at its facilities from time to time. The
company establishes and maintains reserves for such remediation activities, when
appropriate. Current reserves established for known or probable remediation
activities are not material to the company's financial position or results of
operations.

FORWARD-LOOKING STATEMENTS

         In an effort to give investors a well-rounded view of the company's
current condition and future opportunities, management's discussion and analysis
of the results of operations and financial condition and other sections of this
Form 10-Q contain "forward-looking statements" about its prospects for the
future. The statements that are not historical facts are "forward-looking
statements" within the meaning of the Private Securities Litigation Reform Act
of 1995. These statements usually are accompanied by words such as "outlook,"
"believe," "estimate," "plan," "project," "expect," "anticipate," "predict,"
"could," "should," "may," or similar words that convey the uncertainty of future
events or outcomes. These statements are based on judgments the company believes
are reasonable; however, the company's actual results could differ materially
from those discussed here. Such risks and uncertainties include, but are not
limited to, the following:

         1.       The company's roofing products business is substantially
                  non-cyclical, but can be affected by weather, the availability
                  of financing and general economic conditions. In addition, the
                  asphalt roofing products manufacturing business is highly
                  competitive. Actions of competitors, including changes in
                  pricing, or slowing demand for asphalt roofing products due to
                  general or industry economic conditions or the amount of
                  inclement weather could result in decreased demand for the
                  company's products, lower prices received or reduced
                  utilization of plant facilities. Further, changes in building
                  codes and other standards from time to time can cause changes
                  in demand, or increases in costs that may not be passed
                  through to customers.


                                       11
<PAGE>   13



         2.       In the asphalt roofing products business, the significant raw
                  materials are ceramic-coated granules, asphalt, glass fibers,
                  resins and mineral filler. Increased costs of raw materials
                  can result in reduced margins, as can higher trucking and rail
                  costs. Historically, the company has been able to pass some of
                  the higher raw material and transportation costs through to
                  the customer. Should the company be unable to recover higher
                  raw material and/or transportation costs from price increases
                  of its products, operating results could be adversely affected
                  and/or lower than projected.

         3.       The company plans to continue its significant expansion plan
                  over the next several years, including the construction of new
                  facilities. Progress in achieving anticipated operating
                  efficiencies and financial results is difficult to predict for
                  new plant facilities. If such progress is slower than
                  anticipated, if substantial cost overruns occur in building
                  new plants, or if demand for products produced at new plants
                  does not meet current expectations, operating results could be
                  adversely affected.

         4.       Certain facilities of the company's electronics manufacturing
                  services and industrial products subsidiaries must utilize
                  hazardous materials in their production process. As a result,
                  the company could incur costs for remediation activities at
                  its facilities or off-site, and other related exposures from
                  time to time in excess of established reserves for such
                  activities.

         5.       The company's litigation, including Elk's defense of purported
                  class action lawsuits, is subject to inherent and
                  case-specific uncertainty. The outcome of such litigation
                  depends on numerous interrelated factors, many of which cannot
                  be predicted.

         6.       Although the company currently anticipates that most of its
                  needs for new capital in the near future will be met with
                  internally generated funds or borrowings under its available
                  credit facilities, significant increases in interest rates
                  could substantially affect its borrowing costs under its
                  existing loan facility, or its cost of alternative sources of
                  capital.

         7.       Each of the company's businesses, especially Cybershield's
                  shielding business, is subject to the risks of technological
                  changes that could affect the demand for or the relative cost
                  of the company's products and services, or the method and
                  profitability of the method of distribution or delivery of
                  such products and services. In addition, the company's
                  businesses each could suffer significant setbacks in revenues
                  and operating income if it lost one or more of its largest
                  customers, or if its customers' plans and/or markets should
                  change significantly.

         8.       Although the company insures itself against physical loss to
                  its manufacturing facilities, including business interruption
                  losses, natural or other disasters and accidents, including
                  but not limited to fire, earthquake, damaging winds and
                  explosions, operating results could be adversely affected if
                  any of its manufacturing facilities became inoperable for an
                  extended period of time due to such events.


                                       12
<PAGE>   14


         9.       Each of the company's businesses is actively involved in the
                  development of new products, processes and services which are
                  expected to contribute to the company's ongoing long-term
                  growth and earnings. If such development activities are not
                  successful, or the company cannot provide the requisite
                  financial and other resources to successfully commercialize
                  such developments, the growth of future sales and earnings may
                  be adversely affected.

         Parties are cautioned not to rely on any such forward-looking beliefs
or judgments in making investment decisions.


                                       13
<PAGE>   15

PART II.  OTHER INFORMATION

ITEM 5:  Other Information

         On February 6, 2001, the company announced that the Board of Directors
elected Thomas D. Karol, a member of the Board, as President and Chief Executive
Officer, to succeed Harold K. Work, effective March 26, 2001. Mr. Work will
continue as Chairman of the Board of Directors for a transition period before
retiring.

ITEM 6:  Exhibits and Reports on Form 8-K

         (a)      Exhibits:

                  Exhibit (4.13): First Amendment to Credit Agreement dated as
                  of March 31, 2001 among Elcor Corporation, Bank One, N.A., as
                  Documentation Agent, First Union National Bank, as Syndication
                  Agent, and Bank of America, N.A., as Administrative Agent,
                  Swing Line Lender and L/C Issuer.

         (b)      The registrant filed three reports on Form 8-K during the
                  quarter ended March 31, 2001. The registrant filed Forms 8-K
                  on January 12, 2001, January 18, 2001 and March 15, 2001
                  relating to press releases containing "forward-looking
                  statements" about its prospects for the future and certain
                  other information concerning the company's disclosures under
                  Regulation F-D.


                                       14
<PAGE>   16


                                   SIGNATURES


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


                                                ELCOR CORPORATION



DATE:  May 14, 2001                             /s/ Richard J. Rosebery
       ---------------------                    --------------------------------
                                                Richard J. Rosebery
                                                Vice Chairman, Chief Financial &
                                                Administrative Officer

                                                /s/ Leonard R. Harral
                                                --------------------------------
                                                Leonard R. Harral
                                                Vice President and Chief
                                                Accounting Officer


                                       15
<PAGE>   17
                               INDEX TO EXHIBITS

<TABLE>
<CAPTION>
EXHIBIT
NUMBER                              DESCRIPTION
-------                             -----------
<S>               <C>
Exhibit (4.13):   First Amendment to Credit Agreement dated as of March 31, 2001
                  among Elcor Corporation, Bank One, N.A., as Documentation
                  Agent, First Union National Bank, as Syndication Agent, and
                  Bank of America, N.A., as Administrative Agent, Swing Line
                  Lender and L/C Issuer.
</TABLE>