<PAGE>   1

                                    FORM 10-Q

                UNITED STATES SECURITIES AND EXCHANGE COMMISSION
                             Washington, D. C. 20549


(MARK ONE)

[X] Quarterly Report Pursuant to Section 13 or 15(d) of the Securities Exchange
Act of 1934 For the Quarter Ended September 30, 2000

                                       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:  333-15789
                       -----------


                                 ChemFirst Inc.
           ---------------------------------------------------------
             (Exact name of registrant as specified in its charter)


          Mississippi                                            64-0679456
--------------------------------------------------------------------------------
(State or other jurisdiction of                               (I.R.S. Employer
 incorporation or organization)                              Identification No.)

 700 North Street, Jackson, MS                                   39202-3095
--------------------------------------------------------------------------------
    (Address of principal                                        (Zip Code)
      executive offices)

Registrant's Telephone Number, including Area Code:  601/948-7550
                                                    -------------

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
            ---       ---


          Class                                 Outstanding at October 31, 2000
--------------------------                      --------------------------------
Common Stock, $1 Par Value                                 14,822,504



<PAGE>   2


                                 ChemFirst Inc.
                     Consolidated Balance Sheets (Unaudited)
                            (In Thousands of Dollars)


<TABLE>
<CAPTION>
                                                            September 30     December 31
                                                                2000             1999
                                                            ------------     ------------
<S>                                                         <C>             <C>
Assets:
Current assets
  Cash and cash equivalents                                 $      8,228           14,551
  Accounts receivable                                             50,675           67,913
  Inventories:
   Finished products                                              50,404           36,860
   Work in process                                                 3,190            3,565
   Raw materials and supplies                                     20,373           22,238
                                                            ------------     ------------
      Total inventories                                           73,967           62,663
                                                            ------------     ------------
  Prepaid expenses and other current assets                       10,235            9,794
  Net current assets of discontinued operations                       --            2,532
                                                            ------------     ------------
      Total current assets                                       143,105          157,453
                                                            ------------     ------------
Investments and other assets                                      18,554           19,189
Property, plant and equipment                                    401,545          390,329
  Less: accumulated depreciation and amortization                184,850          164,584
                                                            ------------     ------------
Property, plant and equipment, net                               216,695          225,745
                                                            ------------     ------------
                                                            $    378,354          402,387
                                                            ============     ============


Liabilities and Stockholders' Equity:
Current liabilities
  Notes payable                                             $      8,164            7,668
  Accounts payable                                                21,713           18,919
  Deferred revenue                                                   100              373
  Accrued expenses and other current liabilities                  14,575           17,523
  Net current liabilities of discontinued operations                 322               --
                                                            ------------     ------------
    Total current liabilities                                     44,874           44,483
                                                            ------------     ------------
Long-term debt                                                    37,423           24,224
Other long-term liabilities                                       26,717           26,130
Deferred income taxes                                             22,787           18,178
Minority interest                                                    649              649
Stockholders' equity:
  Common stock                                                    14,869           17,901
  Additional paid-in capital                                      27,370           25,543
  Accumulated other comprehensive income                             270              287
  Retained earnings                                              203,395          244,992
                                                            ------------     ------------
    Total stockholders' equity                                   245,904          288,723
                                                            ------------     ------------
                                                            $    378,354          402,387
                                                            ============     ============
</TABLE>

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


                                       2

<PAGE>   3



                                 ChemFirst Inc.
                Consolidated Statements of Operations (Unaudited)
         (In Thousands of Dollars and Shares, Except Per Share Amounts)


<TABLE>
<CAPTION>
                                                                          3 Months Ended                   9 Months Ended
                                                                            September 30                    September 30
                                                                      --------------------------      --------------------------
                                                                         2000            1999            2000            1999
                                                                      ----------      ----------      ----------      ----------
<S>                                                                   <C>                 <C>            <C>             <C>
  Sales                                                               $   90,548          79,275         285,029         229,460
  Cost of sales                                                           69,349          54,514         212,492         163,066
                                                                      ----------      ----------      ----------      ----------
         Gross margin                                                     21,199          24,761          72,537          66,394

  General, selling and administrative expenses                            13,907          12,805          42,601          36,573
  Research and development expenses                                        1,891           1,914           5,801           5,455
  Other operating income (expense), net                                    3,558            (212)          5,092           2,669
                                                                      ----------      ----------      ----------      ----------
         Operating earnings                                                8,959           9,830          29,227          27,035

  Interest income                                                             91             122             279             945
  Interest expense                                                           755             435           2,156           1,921
  Other expense,  net                                                        (51)           (109)           (111)           (337)
                                                                      ----------      ----------      ----------      ----------
        Earnings from continuing operations before income taxes            8,244           9,408          27,239          25,722
  Income tax expense                                                       3,092           3,446          10,215           9,646
                                                                      ----------      ----------      ----------      ----------
        Earnings from continuing operations                                5,152           5,962          17,024          16,076
        Gain on disposal of business, net of taxes                            --              --           9,656              --
                                                                      ----------      ----------      ----------      ----------
        Net earnings                                                  $    5,152           5,962          26,680          16,076
                                                                      ==========      ==========      ==========      ==========



Earnings per common share:
       Continuing operations                                          $     0.34            0.33            1.06            0.88
       Gain on disposal of business, net of taxes                           0.00            0.00            0.60            0.00
                                                                      ----------      ----------      ----------      ----------
       Net earnings                                                   $     0.34            0.33            1.66            0.88
                                                                      ==========      ==========      ==========      ==========


Average shares outstanding                                                15,253          18,152          15,990          18,266

Earnings  per common share, assuming dilution:
       Continuing operations                                          $     0.33            0.32            1.06            0.87
       Gain on disposal of business, net of taxes                           0.00            0.00            0.59            0.00
                                                                      ----------      ----------      ----------      ----------
       Net earnings                                                   $     0.33            0.32            1.65            0.87
                                                                      ==========      ==========      ==========      ==========


Average shares outstanding, assuming dilution                             15,470          18,411          16,135          18,482

Cash dividend declared
  per share                                                           $     0.10            0.10            0.30            0.30
</TABLE>



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



                                       3

<PAGE>   4


                                 ChemFirst Inc.
                Consolidated Statements of Cash Flows (Unaudited)
                            (In Thousands of Dollars)


<TABLE>
<CAPTION>
                                                                      9 Months Ended
                                                                       September 30
                                                                 --------------------------
                                                                    2000            1999
                                                                 ----------      ----------
<S>                                                              <C>             <C>
Cash flows from operations:
  Net earnings                                                   $   26,680          16,076
  Adjustments to reconcile net earnings  to
   net cash provided by operations:
    Depreciation and amortization                                    21,829          19,523
    Provision for losses on receivables                                  61             133
    Gain on disposal of business, net of taxes                       (9,656)             --
    Gain on disposal of equity investee                                  --            (750)
    Deferred taxes and other items                                    5,411           9,259
    Change in current assets and liabilities, net
     of effects of dispositions                                       3,671         (26,410)
                                                                 ----------      ----------
              Net cash provided by continuing operations             47,996          17,831
              Net cash provided by discontinued operations               --          20,312
                                                                 ----------      ----------
              Net cash provided by operating activities              47,996          38,143
                                                                 ----------      ----------
Cash flows from investing activities:
  Proceeds from sale of business                                     12,582              --
  Capital expenditures                                              (11,215)        (16,932)
  Proceeds from collection of note receivable                         1,468          29,569
  Other investing activities                                           (928)         (3,000)
                                                                 ----------      ----------
              Net cash provided by  investing activities              1,907           9,637
                                                                 ----------      ----------
Cash flows from financing activities:
  Net borrowings (repayments) on notes payable                       13,696         (33,796)
  Dividends                                                          (4,680)         (5,463)
  Purchase of common stock                                          (66,732)         (9,830)
  Proceeds from issuance of common stock                              1,608           1,338
                                                                 ----------      ----------
             Net cash used in financing activities                  (56,108)        (47,751)
                                                                 ----------      ----------
Effect of exchange rate changes on cash                                (118)             75
                                                                 ----------      ----------
Net increase (decrease) in cash and cash equivalents                 (6,323)            104
Cash and cash equivalents at beginning of period                     14,551          11,226
                                                                 ----------      ----------
Cash and cash equivalents at end of period                       $    8,228          11,330
                                                                 ==========      ==========

Supplemental disclosures of cash flow information
  Cash paid during the period for:
    Interest, net of amounts capitalized                         $    1,822           1,909
                                                                 ==========      ==========
    Income tax payments (refunds), net                           $   (3,816)          1,947
                                                                 ==========      ==========
</TABLE>

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


                                       4
<PAGE>   5


ChemFirst Inc. and Subsidiaries
Notes to Consolidated Financial Statements
(Unaudited. In Thousands of Dollars)


Note 1 - General

         The financial statements included herein are unaudited and have been
prepared in accordance with generally accepted accounting principles for interim
financial reporting and Securities and Exchange Commission regulations. Certain
information and footnote disclosures normally included in financial statements
prepared in accordance with generally accepted accounting principles have been
condensed or omitted pursuant to such rules and regulations. Certain prior year
amounts have been reclassified to conform to the 2000 presentation. In the
opinion of management, the financial statements reflect all adjustments (all are
of a normal and recurring nature) which are necessary to present fairly the
financial position, results of operations and cash flows for the interim
periods. These financial statements should be read in conjunction with the
Annual Report of the Company and Form 10-K for the year ended December 31, 1999.

Note 2 - Discontinued Operations

         The net assets and liabilities of discontinued operations included in
the consolidated financial statements are classified as current liabilities and
current assets at September 30, 2000 and December 31,1999, respectively, as
follows:

<TABLE>
<CAPTION>
                                                                 Engineered Products
                                                                    and Services
                                                          Steel       and Other         Totals
                                                       ----------     ----------      ----------
<S>                                                    <C>        <C>                <C>
At September 30, 2000:

Net current liabilities of discontinued operations     $      281             41             322
                                                       ==========     ==========      ==========

At December 31, 1999:

Net current assets of discontinued operations          $   12,459         (9,927)          2,532
                                                       ==========     ==========      ==========
</TABLE>


         The statements of operations have been reclassified to separate
discontinued and continuing operations. The gain on disposal of business in the
first quarter of the current year, net, in the amount of $9,656, was primarily
due to an adjustment in the provision for income taxes related to the
discontinued operations of Getchell Gold Corporation. The Company reevaluated
its tax exposure during the quarter ended March 31, 2000, when various statutes
governing the handling of the disposition for tax purposes expired.



                                       5

<PAGE>   6

Note 3 - Effect Of Adopting Accounting Changes


         In December 1999, the Securities and Exchange Commission ("SEC") issued
Staff Accounting Bulletin ("SAB") No. 101, Revenue Recognition in Financial
Statements. SAB 101 provides guidance on the recognition, presentation, and
disclosure of revenue in financial statements. In June 2000, the SEC issued SAB
No. 101B, Second Amendment: Revenue Recognition in Financial Statements. SAB
101B delays the implementation date of SAB 101 for registrants with fiscal years
that begin between December 16, 1999 and March 15, 2000 until the fourth quarter
of 2000. The Company's existing practice, as outlined by generally accepted
accounting principles, has been to recognize revenue only when realized or
realizable and earned. As such, SAB 101 is not expected to have a material
effect on consolidated financial position or results of operations.


         Statement of Financial Accounting Standards ("SFAS") No. 133 -
"Accounting for Derivative Instruments and Hedging Activities," was issued in
June 1998 and, as amended, is effective for all fiscal quarters of all fiscal
years beginning after June 15, 2000. The statement establishes accounting and
reporting standards for derivative instruments and for hedging activities. All
derivatives are required to be recognized as either assets or liabilities in the
statement of financial position and measured at fair value. Changes in fair
value will be reported either in earnings or outside earnings depending on the
intended use of the derivative and the resulting designation. Entities applying
hedge accounting are required to establish at the inception of the hedge the
method used to assess the effectiveness of the hedging derivative and the
measurement approach for determining the ineffective aspect of the hedge. The
Company currently follows SFAS No. 52, "Foreign Currency Translation," and
applies hedge accounting treatment to certain foreign currency transactions by
entering into foreign currency option contracts and forward exchange contracts.
Gains and losses associated with currency rate changes on contracts hedging
foreign currency transactions are recorded in income and generally offset the
transaction losses or gains on the foreign currency cash flows that they are
intended to hedge. Gains and losses on contracts hedging firm sales commitments
are deferred until the related transactions are consummated. The effect of
adopting the Statement is currently being evaluated, however, based on current
activity, the Company does not believe the effects of adoption will be material
to its financial position or results of operation.


Note 4 - Earnings Per Share

         Basic EPS is based on the average number of common shares outstanding
during each period. Diluted EPS includes the effect of outstanding common stock
equivalents ("CSEs"). The following is a reconciliation of the numerators
(income) and denominators (weighted-average shares) of the basic and diluted per
share computations for net earnings:


<TABLE>
<CAPTION>
                                                 Three Months Ended September 30
                                                  2000                      1999
                                        ------------------------   ------------------------
                                        Income   Shares    EPS     Income   Shares   EPS
                                        ------   ------   ------   ------   ------   ------
                                               (Thousands, except per share amounts)
<S>                                     <C>      <C>      <C>      <C>      <C>      <C>
Earnings per Common Share:
     Basic                              $5,152   15,253   $ 0.34   $5,962   18,152   $ 0.33
     Dilutive effect of CSEs                --      217     (.01)      --      259     (.01)
                                        ------   ------   ------   ------   ------   ------
     Diluted                            $5,152   15,470   $ 0.33   $5,962   18,411   $ 0.32
                                        ======   ======   ======   ======   ======   ======
</TABLE>


                                       6

<PAGE>   7


<TABLE>
<CAPTION>
                                                     Nine Months Ended September 30
                                                   2000                            1999
                                        ---------------------------    ---------------------------
                                        Income    Shares      EPS      Income    Shares      EPS
                                        -------   -------   -------    -------   -------   -------
                                                  (Thousands, except per share amounts)
<S>                                     <C>        <C>      <C>        <C>        <C>      <C>
Earnings per Common Share:
     Basic                              $26,680    15,990   $  1.66    $16,076    18,266   $  0.88
     Dilutive effect of CSEs                 --       145      (.01)        --       216      (.01)
                                        -------   -------   -------    -------   -------   -------
     Diluted                            $26,680    16,135   $  1.65    $16,076    18,482   $  0.87
                                        =======   =======   =======    =======   =======   =======
</TABLE>


Note 5 -  Comprehensive Income

         Total comprehensive income for the three months ended September 30,
2000 and 1999, was $5.1 million and $6.0 million, respectively. Comprehensive
income for the nine months ended September 30, 2000 and 1999, was $26.7 million
and $16.2 million, respectively. Total comprehensive income for the Company
includes net income and foreign currency translation adjustments.


Note 6 -  Commitments and Contingencies


In June 2000 an explosion disrupted the supply of hydroxylamine from the Nissin
Chemical plant in Japan. This is a key ingredient in the Company's patented
HDA(R) remover products for the semiconductor industry. The Nissin plant was the
Company's sole supplier and until last year the only producer of hydroxylamine.
However, the Company has qualified hydroxylamine from a new BASF plant that
started up in late 1999. BASF's current supply capabilities are less than the
worldwide demand for hydroxylamine. As a result, BASF is allocating
hydroxylamine to its customers, including the Company, which in turn has put its
customers on allocation. BASF, which increased production capacity through
debottlenecking efforts in September, has recently announced that it will
further increase capacity during the first quarter of 2001 from 4,000 metric
tons p.a. to 5,700 metric tons p.a. (calculated as a 50% solution). Such
expansion may result in additional supplies of hydroxylamine in the first half
of 2001, however, it is unclear at this time how BASF's increased capacity will
be allocated among its customers, exactly when additional product will be
available and what impact it will have on the Company. Although Nissin and
Honeywell International Inc. have both announced plans to construct new
hydroxylamine plants, the timing for construction and start-up of these
anticipated plants is not known with certainty. An insurance claim to recover
lost profits and additional expenses has been filed under the Company's business
interruption policy. The claims process may be lengthy and its final outcome
cannot be predicted with certainty. At September 30, 2000, $2.4 million, after
meeting a $1 million deductible, was recorded as the initial installment of the
claim. The $2.4 million is reflected in the accompanying consolidated statement
of operations as Other Operating Income.


                                       7

<PAGE>   8

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

Results of Operations - Nine months ended September 30, 2000 compared to the
nine months ended September 30, 1999


Consolidated Results

         Results from continuing operations for the nine months ended September
30, 2000, were earnings of $17.0 million or $1.06 per diluted share, up 6% and
22%, respectively, from earnings of $16.1 million or $0.87 per diluted share
from the same period of the prior year. Earnings rose on better results in
Polyurethane operations, driven by increased volume. Earnings per share were up
due to the higher earnings and a reduction in shares outstanding due to share
repurchases.

Segment Operations

                               Segment Information
                            (In Thousands of Dollars)


<TABLE>
<CAPTION>
                                                        9 Months Ended
                                                         September 30
                                                      2000          1999
                                                   ----------    ----------
<S>                                                <C>              <C>
Sales:
        Electronic and Other Specialty Chemicals   $  149,647       126,646
        Polyurethane Chemicals                        135,382       102,814
                                                   ----------    ----------
               Total                               $  285,029       229,460
                                                   ==========    ==========

Operating profit before income taxes:
        Electronic and Other Specialty Chemicals   $   11,091        12,092
        Polyurethane Chemicals                         26,034        24,060
                                                   ----------    ----------
                                                       37,125        36,152
        Unallocated corporate expenses                 (7,898)       (9,117)
        Interest expense, net                          (1,877)         (976)
        Other expense, net                               (111)         (337)
                                                   ----------    ----------
               Total                               $   27,239        25,722
                                                   ==========    ==========
</TABLE>

         Electronic and Other Specialty Chemicals pretax operating profits for
the current year were $11.1 million, down 8% versus the same period of the prior
year. Sales were up 18% over last year on higher electronic chemical volumes.
Operating results were hurt by higher energy and raw materials costs and lower
volumes and margins in agricultural specialty chemicals. Demand for
semiconductor chemicals remains strong, but sales were hurt by a shortage of
hydroxylamine raw material caused by an explosion in June 2000 at the Nissin
Chemical plant supplying the material. The effect on earnings was offset by net
insurance of $2.4 million, after meeting a $1.0 million deductible. The Company
anticipates that its insurance should significantly reduce lost profits
associated with the disruption.

         Polyurethane Chemicals pretax operating profits for the nine months
were up 8% to $26.0 million on a 32% increase in sales versus the same period
last year. Sales were up on a 5% increase in volume and a 25% increase in
average unit price. The higher volume reflects continued strong

                                       8

<PAGE>   9

aniline demand. The higher unit sales price primarily reflects the pass-through
to customers of the increase in the cost of benzene.

         Unallocated corporate expenses for the current year were $7.9 million,
down from $9.1 million in the prior year, primarily related to a reduction in
benefit expense. Net interest expense for the year was up $0.9 million from the
prior year to $1.9 million on lower interest income.


Results of Operations - Three months ended September 30, 2000
compared to the three months ended September 30, 1999


Consolidated Results

         Results from continuing operations for the three months ended September
30, 2000, were earnings of $5.2 million or $0.33 per diluted share. Results for
the same quarter of the prior year were earnings of $6.0 million or $0.32 per
diluted share. Earnings declined on lower polyurethane chemical volume and
higher costs and lower volumes in agricultural specialty chemicals. Sales were
up 14% for the period, primarily due to higher energy and raw material
pass-throughs. Earnings per share were up on fewer shares outstanding.


                                       9


<PAGE>   10


Segment Operations

                               Segment Information
                            (In Thousands of Dollars)


<TABLE>
<CAPTION>
                                                            3 Months Ended
                                                             September 30
                                                          2000          1999
                                                       ----------    ----------
<S>                                                    <C>           <C>
Sales:
        Electronic and Other Specialty Chemicals       $   42,796        39,231
        Polyurethane Chemicals                             47,752        40,044
                                                       ----------    ----------
               Total                                   $   90,548        79,275
                                                       ==========    ==========

Operating profit before income taxes:
        Electronic and Other Specialty Chemicals       $    3,363         4,251
        Polyurethane Chemicals                              8,135         8,815
                                                       ----------    ----------
                                                           11,498        13,066
        Unallocated corporate expenses                     (2,539)       (3,236)
        Interest expense, net                                (664)         (313)
        Other expense, net                                    (51)         (109)
                                                       ----------    ----------
               Total                                   $    8,244         9,408
                                                       ==========    ==========
</TABLE>


         Electronic and Other Specialty Chemicals pretax operating profits for
the current year were down 21% versus the same quarter of the prior year to $3.4
million, with sales up 9%. Sales were up over last year on higher volumes of
electronic chemical residue removers and deep ultra violet resins. Operating
results were hurt, however, by lower margins in other specialty chemicals,
primarily due to higher energy and raw material costs and product mix.

         Polyurethane Chemicals pretax operating profits for the quarter were
down 8% to $8.1 million versus the same quarter last year. Sales were up 19% as
a 38% increase in average unit price offset a 14% decrease in volume. The higher
unit sales price primarily reflects the pass-through to customers of the
increase in the cost of benzene. The Company's Baytown aniline facility shut
down in mid-October due to an interruption in the supply of nitric acid raw
material but re-started on October 28. . The earnings impact is expected to be
negligible.

         Unallocated corporate expenses for the current quarter were $2.5
million, down from $3.2 million for the same period in the prior year on reduced
insurance and benefit expenses. Net interest expense for the current quarter was
up $0.4 million from the prior year on higher average debt due to current year
share repurchases.

Discontinued Operations

         A gain of $9.7 million on disposal of discontinued operations was
recorded during the quarter ended March 31, 2000. The gain included $10.1
million from a reduction in estimated tax liabilities related to the
distribution of Getchell Gold Corporation in 1995. The reduction in estimated
tax liabilities resulted from the Company's reevaluation of tax exposure items
associated with the Getchell Gold Corporation distribution. The Company
reevaluated its tax exposure during the quarter ended March 31, 2000, when
various statutes governing the handling of the disposition for tax purposes
expired. Also, during the first quarter of the current year, the Company
recorded an additional $0.4 million loss on disposal of discontinued operations
related to final settlement of post-closure issues associated with the
dispositions of Callidus Technology, Inc. and FirstMiss Steel, Inc.


                                       10

<PAGE>   11


Capital Resources and Liquidity

         Cash flow from continuing operations for the current year was $48.0
million, up from $17.8 million in the prior year. Prior year operating cash flow
was lower primarily due to increased working capital. Net cash provided by
investing activities in the current year included $12.6 million in proceeds from
the sale of the Company's steel business and $1.5 million collected on a note
related to a previous property sale. These proceeds were used to assist in
repurchasing shares of the Company's stock. During the current year, $66.7
million was expended under the Company's authorized repurchasing program versus
$9.8 million for the same period of the prior year. The Company has
approximately $23.3 million remaining for additional share repurchases under the
current authorization.



Forward-Looking Statements

         Certain statements included in this Form 10-Q which are not historical
in nature, may constitute "forward-looking statements" within the meaning of the
Private Securities Litigation Reform Act of 1995. Such forward-looking
statements, as well as other forward-looking statements made from time to time
by the Company, or in the Company's press releases, conference calls and filings
with the U.S. Securities and Exchange Commission, are based on certain
underlying assumptions and expectations of management. These forward-looking
statements are subject to risks and uncertainties which could cause actual
results to differ materially from those expressed in such forward-looking
statements. Such risks and uncertainties include, but are not limited to,
general economic conditions, availability and pricing of raw materials including
hydroxylamine and nitric acid, supply/demand balance for key products, new
product development, manufacturing efficiencies, conditions of and product
demand by key customers, the timely completion and start up of construction
projects, pricing pressure as a result of domestic and international market
forces and insurance coverage and timing of any claim payments related to the
disruption in supply of hydroxylamine, the interruption in the supply of nitric
acid at the Baytown, TX facility and other factors as may be discussed in the
company's Form 10-K for the fiscal year ended December 31, 1999.



Item 3. Quantitative and Qualitative Disclosures About Market Risk

         The Company is exposed to changes in financial market conditions in the
normal course of its business, including changes in interest rates and foreign
currency exchange rates. At September 30, 2000, the Company's derivative and
other financial instruments related to foreign operations included a series of
yen option collars representing total option puts and calls of 80 million yen
each, with a minimum U.S. dollar value of $0.7 million and a maximum U.S. dollar
value of $0.9 million, and contract expiration dates ranging from October 2000
through January 2001. The Company also has short-term debt denominated in
Japanese yen with a current U.S. dollar value of $8.2 million. Due to the
short-term nature and amount of these yen obligations, the Company does not
consider its exposure to fluctuations in foreign currency exchange rates or
interest rates to be material.



                                       11

<PAGE>   12

         The Company utilizes fixed and variable-rate debt to maintain liquidity
and fund its domestic business operations, with the terms and amounts based on
business requirements, market conditions and other factors. At September 30,
2000, this included long-term debt denominated in U.S. dollars and long-term
revolving credit facility borrowings. The market value of the Company's fixed
rate borrowings was approximately $24.0 million. A 100 basis point change in
interest rates (all other variables held constant) as of September 30, 2000,
would result in an approximate $1.0 million annualized change in fair market
value but would not affect interest expense or cash flow. At September 30, 2000,
the Company had $13.0 million in variable-rate debt. A 100 basis point change in
interest rates (all other variables held constant) on this portion of the
Company's debt would result in an annualized change in interest expense of
approximately $0.13 million.






                           Part II. Other Information



Item 6. Exhibits and Reports on Form 8-K

            (a) Exhibits

                Exhibit 27 - Financial Data Schedule

                Exhibit 27.1 - Restated Financial Data Schedule

            (b) Reports on Form 8-K

                No report on Form 8-K was filed by the Registrant during the
                three months ended September 30, 2000.







                                       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.




                                 CHEMFIRST INC.



November 13, 2000                  /s/ J. Kelley Williams
------------------                 ----------------------
Date                                   J. Kelley Williams
                                       Chairman and Chief Executive Officer



November 13, 2000                  /s/ Troy B. Browning
-------------------                ---------------------
Date                                   Troy B. Browning
                                       Controller (Principal Accounting Officer)






<PAGE>   14



                               INDEX TO EXHIBITS





<TABLE>
<CAPTION>
          EXHIBIT
          NUMBER              DESCRIPTION
          ------              -----------
<S>                           <C>
           27                 Financial Data Schedule

           27.1               Restated Financial Data Schedule
</TABLE>