SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                  SCHEDULE 13D

                               (AMENDMENT NO. 5)

                   Under the Securities Exchange Act of 1934*

                            Carrizo Oil & Gas, Inc.
-------------------------------------------------------------------------------
                                (Name of Issuer)

                     Common Stock, par value $.01 per share
-------------------------------------------------------------------------------
                         (Title of Class of Securities)

                                  144577 10 3
-------------------------------------------------------------------------------
                                 (CUSIP Number)

                               Steven A. Webster
                            Carrizo Oil & Gas, Inc.
                        14701 St. Mary's Lane, Suite 800
                              Houston, Texas 77079
                                 (281) 496-1352
-------------------------------------------------------------------------------
            (Name, Address and Telephone Number of Person Authorized
                     to Receive Notices and Communications)

                                  June 7, 2004
-------------------------------------------------------------------------------
            (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 that is the subject of this Schedule 13D, and is filing this
schedule because of ss.ss. 240.13d-1(e), 240.13d-1(f) or 240.13d-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-7 for other
parties to whom copies are to be sent.

*The remainder of this cover page should 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).

                                       1


----------------------------------
CUSIP No.  144577 10 3
----------------------------------
1         NAME OF REPORTING PERSON
          S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

          Steven A. Webster
-------------------------------------------------------------------------------
2         CHECK THE APPROPRIATE BOS IF A MEMBER OF A GROUP*
                                                                     (A) [ ]
                                                                     (B) [ ]
-------------------------------------------------------------------------------
3         SEC USE ONLY
-------------------------------------------------------------------------------
4         SOURCE OF FUNDS*

          00
-------------------------------------------------------------------------------
5         CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT
          TO ITEMS 2(d) OR 2(e)
-------------------------------------------------------------------------------
6         CITIZENSHIP OR PLACE OF ORGANIZATION

          United States of America
-------------------------------------------------------------------------------
         NUMBER OF       7      SOLE VOTING POWER

          SHARES                2,515,835 shares (720,402 are issuable upon the
                                exercise of certain options and warrants and
                                conversion of preferred stock)
       BENEFICIALLY      ------------------------------------------------------
                         8      SHARED VOTING POWER
        OWNED BY
                                0 shares
          EACH           ------------------------------------------------------
                         9      SOLE DISPOSITIVE POWER
        REPORTING
                                2,515,835 shares (720,402 are issuable upon the
                                exercise of certain options and warrants and
         PERSON                 conversion of preferred stock)
                         ------------------------------------------------------
          WITH           10    SHARED DISPOSITIVE POWER

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

          2,515,835 shares
-------------------------------------------------------------------------------
12        CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN
          SHARES*                                                        [ ]
-------------------------------------------------------------------------------
13        PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 11

          11.4%
-------------------------------------------------------------------------------
14        TYPE OF REPORTING PERSON*

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


                                       2

INTRODUCTORY NOTE.

                  This Amendment No. 5 to Schedule 13D is being filed on behalf
Steven A. Webster ("Mr. Webster") to supplement certain information set forth
in the Schedule 13D relating to securities of Carrizo Oil & Gas, Inc., a Texas
corporation (the "Company"), originally filed by Mr. Webster on August 21, 1997
and amended by Amendment No. 1 dated January 8, 1998, Amendment No. 2 dated
March 13, 1998, Amendment No. 3 dated December 15, 1999 and Amendment No. 4
dated February 20, 2002 (as so amended, the "Original Statement"), with respect
to the Common Stock, par value $.01 per share (the "Common Stock"), of the
Company. Unless otherwise indicated, each capitalized term used but not defined
herein shall have the meaning assigned to such term in the Original Statement.

ITEM 4.           PURPOSE OF TRANSACTION.

                  As more fully described in Item 5, effective June 7, 2004,
Mr. Webster transferred all of his interest in a 9% Senior Subordinated Note
due 2007 (the "Note") issued by the Company and held by him to a third-party
unaffiliated purchaser (the "Purchaser").

                  As more fully described in Item 5, effective June 30, 2004,
Mr. Webster has provided notice to the Company to convert all of the shares of
Series B Convertible Preferred Stock (the "Preferred Stock") of the Company
held by him into Common Stock of the Company.

ITEM 5.       INTEREST IN SECURITIES OF THE ISSUER.

                  Mr. Webster beneficially owns an aggregate of 2,515,835
shares of Common Stock (approximately 11.4% of the 22,004,552 shares deemed to
be outstanding as of June 18, 2004 (consisting of 21,284,150 shares of Common
Stock currently outstanding and 278,377 shares of Common Stock that can be
acquired through the exercise of options and warrants within 60 days of June
18, 2004 and 442,025 shares of Common Stock that can be acquired through the
conversion of the Preferred Stock)).

                  Effective June 7, 2004, pursuant to the Note Purchase
Agreement dated as of June 7, 2004 among the Purchaser, Mr. Webster and certain
noteholders named therein, Mr. Webster transferred all of his interest in the
Note to the Purchaser for an amount equal to the principal and accrued interest
on the Note as of June 7, 2004, or $938,881. Further information regarding this
transaction is provided in the Company's Current Report on Form 8-K filed with
the Securities and Exchange Commission on June 10, 2004.

                  As described under Item 6, as a result of Mr. Webster's
release from the shareholders agreements, beneficial ownership of Common Stock
held by other shareholders who are party to the shareholders agreements may not
be attributable to Mr. Webster.

                  On June 18, 2004, pursuant to a Warrant Agreement dated
December 15, 1999 among the Company, Mr. Webster and certain warrantholders
listed therein, Mr. Webster fully exercised a warrant (the "Warrant") to
purchase 92,006 shares of Common Stock of the Company at $2.20 per share held
by him on a "cashless" "net exercise" basis. As a result of such net exercise,
Mr. Webster received 70,205 shares of Common Stock underlying the Warrant.

                  Mr. Webster has delivered a notice to the Company providing
that, effective June 30, 2004, pursuant to the Statement of Resolution
Establishing Series of Shares designated Series B Convertible Participating
Preferred Stock (the "Statement of Resolution"), which includes the right to
convert the Preferred Stock into Common Stock at a price of $5.70 per share,
subject to adjustments, Mr. Webster will convert all of the 25,195.45 shares of
Preferred Stock held by him into 442,025 shares of Common Stock. Mr. Webster
had acquired the Preferred Stock pursuant to a Securities Purchase Agreement
dated February 20, 2002 (the "Securities Purchase Agreement") among the
Company, Mellon Ventures, L.P. and Steven A. Webster. Copies of the Securities
Purchase Agreement and the Statement of Resolution were filed previously as
Exhibits 22 and 23, respectively, to the Original Statement.

                                       3


ITEM 6.       CONTRACTS, ARRANGEMENTS, UNDERSTANDINGS OR RELATIONSHIPS WITH
              RESPECT TO SECURITIES OF THE ISSUER.

                  Effective June 7, 2004, the Shareholders Agreement dated
December 15, 1999 (the "1999 Shareholders Agreement") by and among the Company,
Mr. Webster and certain other shareholders named therein was amended so that
each of Mr. Webster, Mellon Ventures, L.P., Frank A. Wojtek and S.P. Johnson IV
(the "Exiting Shareholders") ceased to be party to the 1999 Shareholders
Agreement; and, as a result, the Exiting Shareholders have no remaining rights
or obligations thereunder. Effective June 7, 2004, the Shareholders Agreement
dated February 20, 2002 (the "2002 Shareholders Agreement" and together with
the 1999 Shareholders Agreement, the "Shareholders Agreements") by and among
the Company, Mr. Webster and certain other shareholders named therein was
terminated by agreement of the parties; and, as a result, the parties have no
outstanding rights or obligations under the 2002 Shareholders Agreement. The
parties to the Shareholders Agreements could have been deemed to form a group
pursuant to Rule 13d-5(b)(1) promulgated under the Securities Exchange Act of
1934, as amended (the "Exchange Act"). As a result of Mr. Webster's release
from the Shareholders Agreements, beneficial ownership of Common Stock held by
other parties to the Shareholders Agreements may not be attributable to Mr.
Webster.

                  The foregoing descriptions of the Note Purchase Agreement and
the amendment of the 1999 Shareholders Agreement and termination of the 2002
Shareholders Agreement are qualified by reference to the complete agreements
which are exhibits hereto and are incorporated herein by reference.


ITEM 7.       MATERIAL TO BE FILED AS EXHIBITS.

         Exhibit 33   Note Purchase Agreement dated as of June 7, 2004 among
                      Steelhead Investments Ltd., Douglas A.P. Hamilton, Paul B.
                      Loyd, Jr., Steven A. Webster and Mellon Ventures, L.P.

         Exhibit 34   Second Amendment to Shareholders Agreement dated as of
                      June 7, 2004 by and among Carrizo Oil & Gas, Inc., J.P.
                      Morgan Partners (23A SBIC), LLC, Mellon Ventures, L.P.,
                      S.P. Johnson IV, Frank A. Wojtek and Steven A. Webster
                      (incorporated herein by reference to the Company's Current
                      Report on Form 8-K filed on June 10, 2004).

         Exhibit 35   Termination Agreement dated as of June 7, 2004 by and
                      among Carrizo Oil & Gas, Inc., Mellon Ventures, L.P., S.P.
                      Johnson IV, Frank A. Wojtek and Steven A. Webster
                      (incorporated herein by reference to the Company's Current
                      Report on Form 8-K filed on June 10, 2004).

                  After reasonable inquiry and to the best of his knowledge and
belief, the undersigned certifies that the information set forth in this
statement is true, complete and correct.

Date:  June 25, 2004.
                                               /s/ Steven A. Webster
                                               --------------------------
                                               Steven A. Webster

                                       4