EXHIBIT 3.1


                                 AMENDMENT NO. 3

                                       TO

                                       THE

                              AMENDED AND RESTATED

                                     BYLAWS

                                       OF

                             CARRIZO OIL & GAS, INC.


                  The following Amendment No. 3 to the Amended and Restated
Bylaws, is adopted by the Board of Directors of Carrizo Oil & Gas, Inc. (the
"Corporation") as of February 20, 2002:

         1. Article V, Section 9 of the Amended and Restated Bylaws is amended
by replacing the definition of "Change of Control" in its entirety with the
following:

                  "Change in Control" means a change in control of the
         Corporation occurring after the date of adoption of these Amended and
         Restated Bylaws of a nature that would be required to be reported in
         response to Item 6(e) of Schedule 14A of Regulation 14A (or in response
         to any similar item on any similar schedule or form) promulgated under
         the Exchange Act, whether or not the Corporation is then subject to
         such reporting requirement; provided, however, that, without
         limitation, such a Change in Control shall be deemed to have occurred
         if at any time after the date of adoption of these Amended and Restated
         Bylaws (i) any "person" (as such term is used in Sections 13(d) and
         14(d) of the Exchange Act) is or becomes the "beneficial owner" (as
         defined in Rule 13d-3 under the Exchange Act), directly or indirectly,
         of securities of the Corporation representing 40% or more of the
         combined voting power of the Corporation's then outstanding securities
         without the prior approval of at least two-thirds of the members of the
         Board of Directors in office immediately prior to such person attaining
         such percentage interest; (ii) the Corporation is a party to a merger,
         consolidation, share exchange, sale of assets or other reorganization,
         or a proxy contest, as a consequence of which members of the Board of
         Directors in office immediately prior to such transaction or event
         constitute less than a majority of the Board of Directors thereafter or
         (iii) during any 15-month period, individuals who at the beginning of
         such period constituted the Board of Directors (including for this
         purpose any new director whose election or nomination for election by
         the Corporation's shareholders was approved by a vote of at least
         two-thirds of the

         directors then still in office who were directors at the beginning of
         such period) cease for any reason to constitute at least a majority of
         the Board of Directors.

                  Nothing in the Shareholders Agreement dated December 15, 1999
         among S.P. Johnson IV, Frank A. Wojtek, Paul B. Loyd, Jr., Douglas A.P.
         Hamilton, Steven A. Webster, CB Capital Investors, L.P. ("Chase") and
         certain other investors (the "Shareholders Agreement") or in the
         transactions contemplated by the Securities Purchase Agreement dated
         December 15, 1999 among Paul B. Loyd, Jr., Douglas A.P. Hamilton,
         Steven A. Webster, Chase and certain other investors, as it may be
         amended from time to time (including the addition of any new parties
         thereto), shall constitute a "Change of Control" within the definition
         in this Section 9. Without limiting the generality of the foregoing, no
         "Change of Control" shall result from the attribution of beneficial
         ownership directly or indirectly through the Shareholders Agreement
         such that a shareholder is deemed to beneficially own 40% or more of
         the shares of the Company's common stock then outstanding (a "40%
         Holder"), unless such shareholder would be deemed to be a 40% Holder in
         the absence of the Shareholders Agreement.

                  Nothing in the Shareholders Agreement dated February __, 2002
         among S.P. Johnson IV, Frank A. Wojtek, Paul B. Loyd, Jr., Douglas A.P.
         Hamilton, Steven A. Webster, Mellon Ventures, L.P. ("Mellon") and
         certain other investors (the "Shareholders Agreement") or in the
         transactions contemplated by the Securities Purchase Agreement dated
         February __, 2002 among Steven A. Webster, Mellon and certain other
         investors, as it may be amended from time to time (including the
         addition of any new parties thereto), shall constitute a "Change of
         Control" within the definition in this Section 9. Without limiting the
         generality of the foregoing, no "Change of Control" shall result from
         the attribution of beneficial ownership directly or indirectly through
         the Shareholders Agreement such that a shareholder is deemed to
         beneficially own 40% or more of the shares of the Company's common
         stock then outstanding (a "40% Holder"), unless such shareholder would
         be deemed to be a 40% Holder in the absence of the Shareholders
         Agreement.

         2. Amendment No. 2 to the Amended and Restated Bylaws, as adopted by
the Board of Directors of the Corporation on December 15, 2001, incorrectly
referred to the "Change in Control" provision as "Article IV" and is hereby
corrected to refer to such provision as "Article V."