<PAGE>
    AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON JANUARY 28, 2003.

                                                     REGISTRATION NO. 333-
                                                                          -----
================================================================================
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                   ----------

                                    FORM S-8
                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933

                                   ----------

                             PETROQUEST ENERGY, INC.
             (Exact name of registrant as specified in its charter)

                                   ----------

               DELAWARE                                      76-1440714
     (State or Other Jurisdiction                         (I.R.S. Employer
   of Incorporation or Organization)                    Identification No.)


                     400 E. KALISTE SALOOM ROAD, SUITE 6000
                           LAFAYETTE, LOUISIANA 70508
                    (Address of Principal Executive Offices)


                             PETROQUEST ENERGY, INC.
                               1998 INCENTIVE PLAN

                            (Full Title of the Plan)

                                   ----------

     Name, Address and Telephone                      Copy of Communications to:
     Number of Agent for Service:

         DANIEL G. FOURNERAT                                ROBERT G. REEDY
SENIOR VICE PRESIDENT, GENERAL COUNSEL                  PORTER & HEDGES, L.L.P.
            AND SECRETARY                                700 LOUISIANA STREET
       PETROQUEST ENERGY, INC.                         HOUSTON, TEXAS 77002-2764
400 E. KALISTE SALOOM ROAD, SUITE 6000                      (713) 226-0600
      LAFAYETTE, LOUISIANA 70508
            (337) 232-7028

<Table>
<Caption>
                                           CALCULATION OF REGISTRATION FEE
=================================================================================================================
                                          AMOUNT TO       PROPOSED MAXIMUM        PROPOSED
 TITLE OF SECURITIES                   ----------------       OFFERING        MAXIMUM AGGREGATE       AMOUNT OF
 TO BE REGISTERED(1)                   BE REGISTERED(1)  PRICE PER SHARE(2)   OFFERING PRICE(2)  REGISTRATION FEE
-----------------------------------------------------------------------------------------------------------------
<S>                                       <C>            <C>                  <C>                <C>
Common Stock, par value $.001 per share   503,607(3)           $3.80             $1,913,707            $177
=================================================================================================================
</Table>

(1)      Pursuant to Rule 416(a), also registered hereunder is an indeterminate
         number of shares of common stock issuable as a result of the
         anti-dilution provisions of the PetroQuest Energy, Inc. 1998 Incentive
         Plan (the "Plan").

(2)      Pursuant to Rule 457(c), the registration fee is calculated on the
         basis of the average of the high and low sale prices for the common
         stock on The Nasdaq Stock Market on January 24, 2003, $3.80. Pursuant
         to General Instruction E to Form S-8, the registration fee is
         calculated only with respect to additional securities registered under
         the Plan.

(3)      Includes one preferred share purchase right (the "Rights") for each
         share of common stock. Pursuant to Rule 457(g) of the Securities Act no
         separate fee is required for the Rights.


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

<PAGE>



  STATEMENT UNDER GENERAL INSTRUCTION E - REGISTRATION OF ADDITIONAL SECURITIES

         This registration statement registers an additional 503,607 shares of
our common stock related to the 1998 Incentive Plan which are the same class as
other securities for which registration statements on Form S-8, File No.
333-65401, File No. 333-52700, File No. 333-67578 and File No. 333-88846 (the
"Prior Registration Statements"), have been previously filed. Pursuant to
General Instruction E of Form S-8, the contents of the Prior Registration
Statements are hereby incorporated by reference.

         On June 15, 2002, Arthur Andersen LLP, our former independent auditors,
was convicted of federal obstruction of justice. On June 28, 2002, our Board of
Directors, upon the approval of its Audit Committee, engaged Ernst & Young, LLP
as independent auditors and dismissed Arthur Andersen LLP. After reasonable
efforts, we have not been able to obtain the consent of Arthur Andersen LLP to
the incorporation by reference of its audit report dated March 7, 2002 into this
registration statement. As permitted under Rule 437a promulgated under the
Securities Act of 1933, as amended (the "Securities Act"), we have not filed the
written consent of Arthur Andersen LLP that would otherwise be required by the
Securities Act. Because Arthur Andersen LLP has not consented to the inclusion
of their report in this registration statement, you may not be able to recover
amounts from Arthur Andersen LLP under Section 11(a) of the Securities Act for
any untrue statement of a material fact or any omission to state a material
fact, if any, contained in or omitted from our financial statements included in
our Annual Report on Form 10-K for the fiscal year ended December 31, 2001,
which are incorporated by reference in this registration statement.

ITEM 8. EXHIBITS

<Table>
<Caption>
 EXHIBIT
    NO.        DESCRIPTION
----------     ------------
<S>            <C>
       4.1     PetroQuest Energy, Inc. 1998 Incentive Plan (incorporated herein
               by reference to Appendix A of the Proxy Statement on Schedule 14A
               filed April 20, 2001).

      *5.1     Opinion of Porter & Hedges, L.L.P. with respect to the legality
               of the securities.

     *23.1     Consent of Porter & Hedges, L.L.P. (included in Exhibit 5.1).

     *24.1     Power of Attorney (included on signature page of this
               registration statement).
</Table>

----------
* Filed herewith.



                                       2
<PAGE>



                                   SIGNATURES

         Pursuant to the requirements of the Securities Act of 1933, the
registrant certifies that it has reasonable grounds to believe that it meets all
of the requirements for filing on Form S-8 and has duly caused this registration
statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of Lafayette, State of Lousiana, on this 28th day of
January, 2003.

                                     PETROQUEST ENERGY, INC.


                                     By:     /s/ Charles T. Goodson
                                        --------------------------------------
                                        Charles T. Goodson,
                                        Chairman of the Board, Chief Executive
                                        Officer and Director


                                POWER OF ATTORNEY

         KNOW ALL MEN BY THESE PRESENTS, that each person whose signature
appears below constitutes and appoints Charles T. Goodson, Michael O. Aldridge
and Daniel G. Fournerat, and each of them, either of whom may act without
joinder of the other, his true and lawful attorneys-in-fact and agents, with
full power of substitution and resubstitution, for him and in his name, place
and stead, in any and all capacities, to sign any or all pre- and post-effective
amendments and supplements to this registration statement, and to file the same,
or cause to be filed the same, with all exhibits thereto, and other documents in
connection therewith, with the Securities and Exchange Commission, granting unto
such attorneys-in-fact and agents, and each of them, full power and authority to
do and perform each and every act and thing requisite and necessary to be done
in and about the premises, as fully to all intents and purposes as he might or
could do in person, hereby ratifying and confirming all that said
attorneys-in-fact and agents, and each of them, or the substitute or substitutes
of either of them, may lawfully do or cause to be done by virtue hereof.

         Pursuant to the Securities Act of 1933, this registration statement has
been signed by the following persons in the capacities and on the date
indicated.

<Table>
<Caption>
              SIGNATURE                                         TITLE                                 DATE
              ---------                                         -----                                 ----
<S>                                       <C>                                                      <C>
       /s/ Charles T. Goodson             Chairman of the Board, Chief Executive Officer           January 28, 2003
--------------------------------------    and Director (Principal Executive Officer)
         Charles T. Goodson

      /s/ Alfred J. Thomas, II            President, Chief Operating Officer and Director          January 28, 2003
--------------------------------------
        Alfred J. Thomas, II

         /s/ Ralph J. Daigle              Executive Vice President and Director                    January 28, 2003
--------------------------------------
           Ralph J. Daigle

       /s/ Michael O. Aldridge            Senior Vice President, Chief Financial Officer,          January 28, 2003
--------------------------------------    Treasurer and Director  (Principal Financial and
         Michael O. Aldridge              Accounting Officer)

      /s/ William W. Rucks, IV            Director                                                 January 28, 2003
--------------------------------------
        William W. Rucks, IV

        /s/ E. Wayne Nordberg             Director                                                 January 28, 2003
--------------------------------------
          E. Wayne Nordberg

         /s/ Jay B. Langner               Director                                                 January 27, 2003
--------------------------------------
           Jay B. Langner
</Table>



                                       3
<PAGE>



                                INDEX TO EXHIBITS

<Table>
<Caption>
 EXHIBIT
   NO.         DESCRIPTION
----------     -----------
<S>            <C>
       4.1     PetroQuest Energy, Inc. 1998 Incentive Plan (incorporated herein
               by reference to Appendix A of the Proxy Statement on Schedule 14A
               filed April 20, 2001).

      *5.1     Opinion of Porter & Hedges, L.L.P. with respect to the legality
               of the securities.

     *23.1     Consent of Porter & Hedges, L.L.P. (included in Exhibit 5.1).

     *24.1     Power of Attorney (included on signature page of this
               registration statement).
</Table>

----------
*  Filed herewith.



                                       4
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{"company-data": {"conformed-name": "PETROQUEST ENERGY INC", "cik": "0000872248", "assigned-sic": "1311", "irs-number": "980115468", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-102758", "film-number": "03527042"}, "business-address": {"street1": "400 E KALISTE SALOOM RD SUITE 6000", "city": "LAFAYETTE", "state": "LA", "zip": "70508", "phone": "3372327028"}, "mail-address": {"street1": "600 595 HOWE ST", "city": "VANCOUVER BC CANADA", "state": "A1", "zip": "V6C 2T5"}, "former-company": {"former-conformed-name": "OPTIMA PETROLEUM CORP", "date-changed": "19950726"}}
AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON JANUARY 28, 2003.

                                                     REGISTRATION NO. 333-
                                                                          -----
================================================================================
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                   ----------

                                    FORM S-8
                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933

                                   ----------

                             PETROQUEST ENERGY, INC.
             (Exact name of registrant as specified in its charter)

                                   ----------

               DELAWARE                                      76-1440714
     (State or Other Jurisdiction                         (I.R.S. Employer
   of Incorporation or Organization)                    Identification No.)

                     400 E. KALISTE SALOOM ROAD, SUITE 6000
                           LAFAYETTE, LOUISIANA 70508
                    (Address of Principal Executive Offices)

                             PETROQUEST ENERGY, INC.
                               1998 INCENTIVE PLAN

                            (Full Title of the Plan)

                                   ----------

     Name, Address and Telephone                      Copy of Communications to:
     Number of Agent for Service:

         DANIEL G. FOURNERAT                                ROBERT G. REEDY
SENIOR VICE PRESIDENT, GENERAL COUNSEL                  PORTER & HEDGES, L.L.P.
            AND SECRETARY                                700 LOUISIANA STREET
       PETROQUEST ENERGY, INC.                         HOUSTON, TEXAS 77002-2764
400 E. KALISTE SALOOM ROAD, SUITE 6000                      (713) 226-0600
      LAFAYETTE, LOUISIANA 70508
            (337) 232-7028
CALCULATION OF REGISTRATION FEE
=================================================================================================================
                                          AMOUNT TO       PROPOSED MAXIMUM        PROPOSED
 TITLE OF SECURITIES                   ----------------       OFFERING        MAXIMUM AGGREGATE       AMOUNT OF
 TO BE REGISTERED(1)                   BE REGISTERED(1)  PRICE PER SHARE(2)   OFFERING PRICE(2)  REGISTRATION FEE
-----------------------------------------------------------------------------------------------------------------
Common Stock, par value $.001 per share   503,607(3)           $3.80             $1,913,707            $177
=================================================================================================================
(1)      Pursuant to Rule 416(a), also registered hereunder is an indeterminate
         number of shares of common stock issuable as a result of the
         anti-dilution provisions of the PetroQuest Energy, Inc. 1998 Incentive
         Plan (the "Plan").

(2)      Pursuant to Rule 457(c), the registration fee is calculated on the
         basis of the average of the high and low sale prices for the common
         stock on The Nasdaq Stock Market on January 24, 2003, $3.80. Pursuant
         to General Instruction E to Form S-8, the registration fee is
         calculated only with respect to additional securities registered under
         the Plan.

(3)      Includes one preferred share purchase right (the "Rights") for each
         share of common stock. Pursuant to Rule 457(g) of the Securities Act no
         separate fee is required for the Rights.

================================================================================
STATEMENT UNDER GENERAL INSTRUCTION E - REGISTRATION OF ADDITIONAL SECURITIES

         This registration statement registers an additional 503,607 shares of
our common stock related to the 1998 Incentive Plan which are the same class as
other securities for which registration statements on Form S-8, File No.
333-65401, File No. 333-52700, File No. 333-67578 and File No. 333-88846 (the
"Prior Registration Statements"), have been previously filed. Pursuant to
General Instruction E of Form S-8, the contents of the Prior Registration
Statements are hereby incorporated by reference.

         On June 15, 2002, Arthur Andersen LLP, our former independent auditors,
was convicted of federal obstruction of justice. On June 28, 2002, our Board of
Directors, upon the approval of its Audit Committee, engaged Ernst & Young, LLP
as independent auditors and dismissed Arthur Andersen LLP. After reasonable
efforts, we have not been able to obtain the consent of Arthur Andersen LLP to
the incorporation by reference of its audit report dated March 7, 2002 into this
registration statement. As permitted under Rule 437a promulgated under the
Securities Act of 1933, as amended (the "Securities Act"), we have not filed the
written consent of Arthur Andersen LLP that would otherwise be required by the
Securities Act. Because Arthur Andersen LLP has not consented to the inclusion
of their report in this registration statement, you may not be able to recover
amounts from Arthur Andersen LLP under Section 11(a) of the Securities Act for
any untrue statement of a material fact or any omission to state a material
fact, if any, contained in or omitted from our financial statements included in
our Annual Report on Form 10-K for the fiscal year ended December 31, 2001,
which are incorporated by reference in this registration statement.

ITEM 8. EXHIBITS
EXHIBIT
    NO.        DESCRIPTION
----------     ------------
4.1     PetroQuest Energy, Inc. 1998 Incentive Plan (incorporated herein
               by reference to Appendix A of the Proxy Statement on Schedule 14A
               filed April 20, 2001).

      *5.1     Opinion of Porter & Hedges, L.L.P. with respect to the legality
               of the securities.

     *23.1     Consent of Porter & Hedges, L.L.P. (included in Exhibit 5.1).

     *24.1     Power of Attorney (included on signature page of this
               registration statement).
----------
* Filed herewith.

                                       2
SIGNATURES

         Pursuant to the requirements of the Securities Act of 1933, the
registrant certifies that it has reasonable grounds to believe that it meets all
of the requirements for filing on Form S-8 and has duly caused this registration
statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of Lafayette, State of Lousiana, on this 28th day of
January, 2003.

                                     PETROQUEST ENERGY, INC.

                                     By:     /s/ Charles T. Goodson
                                        --------------------------------------
                                        Charles T. Goodson,
                                        Chairman of the Board, Chief Executive
                                        Officer and Director

                                POWER OF ATTORNEY

         KNOW ALL MEN BY THESE PRESENTS, that each person whose signature
appears below constitutes and appoints Charles T. Goodson, Michael O. Aldridge
and Daniel G. Fournerat, and each of them, either of whom may act without
joinder of the other, his true and lawful attorneys-in-fact and agents, with
full power of substitution and resubstitution, for him and in his name, place
and stead, in any and all capacities, to sign any or all pre- and post-effective
amendments and supplements to this registration statement, and to file the same,
or cause to be filed the same, with all exhibits thereto, and other documents in
connection therewith, with the Securities and Exchange Commission, granting unto
such attorneys-in-fact and agents, and each of them, full power and authority to
do and perform each and every act and thing requisite and necessary to be done
in and about the premises, as fully to all intents and purposes as he might or
could do in person, hereby ratifying and confirming all that said
attorneys-in-fact and agents, and each of them, or the substitute or substitutes
of either of them, may lawfully do or cause to be done by virtue hereof.

         Pursuant to the Securities Act of 1933, this registration statement has
been signed by the following persons in the capacities and on the date
indicated.
SIGNATURE                                         TITLE                                 DATE
              ---------                                         -----                                 ----
/s/ Charles T. Goodson             Chairman of the Board, Chief Executive Officer           January 28, 2003
--------------------------------------    and Director (Principal Executive Officer)
         Charles T. Goodson

      /s/ Alfred J. Thomas, II            President, Chief Operating Officer and Director          January 28, 2003
--------------------------------------
        Alfred J. Thomas, II

         /s/ Ralph J. Daigle              Executive Vice President and Director                    January 28, 2003
--------------------------------------
           Ralph J. Daigle

       /s/ Michael O. Aldridge            Senior Vice President, Chief Financial Officer,          January 28, 2003
--------------------------------------    Treasurer and Director  (Principal Financial and
         Michael O. Aldridge              Accounting Officer)

      /s/ William W. Rucks, IV            Director                                                 January 28, 2003
--------------------------------------
        William W. Rucks, IV

        /s/ E. Wayne Nordberg             Director                                                 January 28, 2003
--------------------------------------
          E. Wayne Nordberg

         /s/ Jay B. Langner               Director                                                 January 27, 2003
--------------------------------------
           Jay B. Langner
3
INDEX TO EXHIBITS
EXHIBIT
   NO.         DESCRIPTION
----------     -----------
4.1     PetroQuest Energy, Inc. 1998 Incentive Plan (incorporated herein
               by reference to Appendix A of the Proxy Statement on Schedule 14A
               filed April 20, 2001).

      *5.1     Opinion of Porter & Hedges, L.L.P. with respect to the legality
               of the securities.

     *23.1     Consent of Porter & Hedges, L.L.P. (included in Exhibit 5.1).

     *24.1     Power of Attorney (included on signature page of this
               registration statement).
----------
*  Filed herewith.

                                       4