--------------------------                            --------------------------
71649P102                                                            Page 1 of 7
--------------------------                            --------------------------


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

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

                                  SCHEDULE 13D

          Under the Securities Exchange Act of 1934 (Amendment No. 4)*
                             _______________________

                              PETROKAZAKHSTAN INC.
                                (Name of Issuer)

                       CLASS A COMMON STOCK, NO PAR VALUE
                         (Title of Class of Securities)


                                    71649P102
                                 (CUSIP Number)

                               BERNARD F. ISAUTIER
                        CHAIRMAN OF THE BOARD, PRESIDENT
                           AND CHIEF EXECUTIVE OFFICER
                            C/O PETROKAZAKHSTAN INC.
                        HOGART HOUSE, 29-31 SHEET STREET
                           WINDSOR, BERKSHIRE, SL4 1BY
                                 UNITED KINGDOM
                           TEL. NO.: 44 (1753) 410 020
                     (Name, Address and Telephone Number of
                      Person Authorized to Receive Notices
                               and Communications)

                                 MARCH 31, 2005
                      (Date of Event which Requires Filing
                               of this Statement)

If the filing person has previously filed a statement on Schedule 13G to report
the acquisition which is the subject of this Schedule 13D, and is filing this
schedule because of Rule 13d-1(e), 1(f) or 1(g), check the following box [ ].

Note: Schedules filed in paper format shall include a signed original and five
copies of the schedule, including all exhibits. See Rule 13d-1(a) for other
parties to whom copies are to be sent.

*The remainder of this cover page shall be filled out for a reporting person's
initial filing on this form with respect to the subject class of securities, and
for any subsequent amendment containing information which would alter
disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the Securities Exchange Act of
1934 ("Act") or otherwise subject to the liabilities of that section of the Act
but shall be subject to all other provisions of the Act (however, see the
Notes).

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



--------------------------                            --------------------------
71649P102                                                            Page 2 of 7
--------------------------                            --------------------------


--------------------------------------------------------------------------------
1        NAME OF REPORTING PERSON
         S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

         Bernard F. Isautier
--------------------------------------------------------------------------------
2        CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP       (a)     [_]
                                                                (b)     [_]

--------------------------------------------------------------------------------
3        SEC USE ONLY


--------------------------------------------------------------------------------
4        SOURCE OF FUNDS

         PF
--------------------------------------------------------------------------------
5        CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO
         ITEMS 2(d) or 2(e)
                                                                        [_]
--------------------------------------------------------------------------------
6        CITIZENSHIP OR PLACE OF ORGANIZATION

         Canadian
--------------------------------------------------------------------------------
                                7       SOLE VOTING POWER

                                        2,431,073
                                ------------------------------------------------
       NUMBER OF                8       SHARED VOTING POWER
        SHARES
    BENEFICIALLY OWNED                  0
    BY EACH REPORTING           ------------------------------------------------
        PERSON                  9       SOLE DISPOSITIVE POWER
         WITH
                                        2,431,073
                                ------------------------------------------------
                                10      SHARED DISPOSITIVE POWER

                                        0
--------------------------------------------------------------------------------
11       AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

         2,431,073
--------------------------------------------------------------------------------
12       CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES

                                                                        [_]
--------------------------------------------------------------------------------
13       PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

         3.20%
--------------------------------------------------------------------------------
14       TYPE OF REPORTING PERSON

         IN
--------------------------------------------------------------------------------



--------------------------                            --------------------------
71649P102                                                            Page 3 of 7
--------------------------                            --------------------------


                         AMENDMENT NO. 4 TO SCHEDULE 13D

                  This Amendment No. 4 amends and restates the Schedule 13D
filed by Mr. Bernard F. Isautier with respect to the Class A Common Stock, no
par value per share (the "Common Stock"), of PetroKazakhstan Inc. (the
"Company"), which was originally filed on March 6, 2002, and amended by
Amendment No. 1, which was filed on May 21, 2004, Amendment No. 2, which was
filed on September 7, 2004, and Amendment No. 3, which was filed on September
30, 2004.

ITEM 1.  SECURITY AND ISSUER.

                  The title of the class of equity securities of the Company to
which this statement relates is the Company's Class A Common Stock, no par
value. The address of the principal executive office of the Company is 140 - 4th
Avenue S.W., #1460, Calgary, Alberta, Canada T2P 3N3.

ITEM 2.  IDENTITY AND BACKGROUND.

                  (a) - (c) The person filing this statement is Bernard F.
Isautier ("Mr. Isautier" or "Reporting Person"). The business address of Mr.
Isautier is c/o PetroKazakhstan Inc., Hogart House, 29-31 Sheet Street, Windsor,
Berkshire, SL4 1BY, United Kingdom. Mr. Isautier's principal occupation or
employment is Chairman of the Board, President and Chief Executive Officer of
the Company.

                  (d) and (e) Mr. Isautier has not, during the last five years,
been (i) convicted in a criminal proceeding (excluding traffic violations or
similar misdemeanors) or (ii) a party to a civil proceeding of a judicial or
administrative body of competent jurisdiction or subject to any judgment, decree
or final order finding any



--------------------------                            --------------------------
71649P102                                                            Page 4 of 7
--------------------------                            --------------------------


violation of federal or state securities laws or enjoining future violations of,
or prohibiting or mandating activities subject to, such laws.

                  (f) Mr. Isautier is a citizen of Canada.

ITEM 3.  SOURCE AND AMOUNT OF FUNDS OR OTHER CONSIDERATION.

                  On March 31, 2005, Mr. Isautier sold a total of 1,075,000
shares of Common Stock in open market transactions for an aggregate amount of
Cdn$ 51,737,500 triggering the filing of this Amendment No. 4 to Schedule 13D.

ITEM 4.  PURPOSE OF TRANSACTION.

                  The Reporting Person disposed of beneficial ownership of the
shares of Common Stock described in this Amendment No. 4 to Schedule 13D for
investment purposes. From time to time the Reporting Person may acquire
additional shares of Common Stock and dispose of some or all of the shares of
Common Stock owned by him. The Reporting Person has no other plans which relate
to or would result in any of the items listed in paragraphs (a) through (j) of
Item 4.

ITEM 5.  INTEREST IN SECURITIES OF THE ISSUER.

                  (a) As of the date hereof, the Reporting Person may be deemed
to beneficially own 2,431,073 shares of Common Stock (including 2,297,740 shares
of Common Stock and options to purchase a further 133,333 shares of Common
Stock), which based on calculations made in accordance with Rule 13d-3(d) of the
Securities Exchange Act of 1934, as amended, and there being 76,002,037 shares
of Common Stock outstanding (as represented by the Company to the Reporting
Person), represent approximately 3.20% of the outstanding shares of Common
Stock.



--------------------------                            --------------------------
71649P102                                                            Page 5 of 7
--------------------------                            --------------------------


                  (b) The Reporting Person has the sole power to direct the vote
and the sole power to direct the disposition of the 2,431,073 shares of Common
Stock that may be deemed to be owned beneficially by him.

                  (c) The shares of Common Stock sold by Mr. Isautier since
September 30, 2004, the date on which Amendment No. 3 to Schedule 13D was filed,
are as follows:

             DATE                NUMBER OF SHARES       PURCHASE PRICE PER SHARE
             ----                ----------------       ------------------------

         March 9, 2005                  100,000              US$44.00

        March 10, 2005                    1,000              Cdn$50.10

        March 10, 2005                      300              Cdn$50.04

        March 10, 2005                  398,700              Cdn$50.00

        March 17, 2005                    1,900              Cdn$50.24

        March 17, 2005                      300              Cdn$50.20

        March 17, 2005                  197,800              Cdn$50.00

        March 31, 2005                  275,000              Cdn$48.50

        March 31, 2005                  500,000              Cdn$48.00

        March 31, 2005                  300,000              Cdn$48.00
                                   ---------------

               TOTAL                  1,775,000

                  The shares were sold in open market transactions.

                  (d) No person other than the Reporting Person has the right to
receive or the power to direct the receipt of dividends from, or the proceeds
from the sale of, the shares of Common Stock owned by the Reporting Person.

                  (e)      Not Applicable.

ITEM 6.  CONTRACTS, ARRANGEMENTS, UNDERSTANDINGS OR RELATIONSHIP WITH RESPECT TO
         THE ISSUER.

                  There are no contracts, arrangements, understandings or
relationships (legal or otherwise) between the person named in Item 2 and any
person with respect to any security of the Company.



--------------------------                            --------------------------
71649P102                                                            Page 6 of 7
--------------------------                            --------------------------


ITEM 7.  MATERIALS TO BE FILED AS EXHIBITS.

                  Not applicable.





--------------------------                            --------------------------
71649P102                                                            Page 7 of 7
--------------------------                            --------------------------


                                   SIGNATURES

             After reasonable inquiry and to the best of my knowledge and
belief, I certify that the information set forth in this statement is true,
complete and correct.

Dated:  April 1, 2005


                                                     /s/ Bernard F. Isautier
                                                     ---------------------------
                                                     Bernard F. Isautier