INCENTIVE PLAN OF CARRIZO OIL & GAS, INC.

                                 Fifth Amendment

     Carrizo  Oil & Gas,  Inc.,  a Texas  corporation  (the  "Company"),  having
reserved the right under Section 13 of the Incentive  Plan of Carrizo Oil & Gas,
Inc. (the "Plan"),  to amend the Plan,  does hereby amend Section 9 of the Plan,
effective as of May 10, 2005, to read in its entirety as follows:

     "9.  Director  Awards.  Each  Nonemployee  Director of the Company shall be
granted  Director  Awards in accordance with this paragraph 9 and subject to the
applicable  terms,  conditions  and  limitations  set forth in this Plan and the
applicable  Director Award Agreement.  Notwithstanding  anything to the contrary
contained  herein,  Director  Awards  shall  not be made in any  year in which a
sufficient  number  of shares of  Common  Stock are not  available  to make such
Awards under this Plan.

     (a)  Director  Options.  On the  date  of a  Nonemployee  Director's  first
appointment  or election to the Board of  Directors  and on or after each Annual
Director Award Date, the Board or the Committee  may, in its  discretion,  grant
such  Nonemployee  Director one or more  Director  Options that provides for the
purchase of such number of shares of Common Stock as the Board or the  Committee
may determine in its discretion,  subject to the limitation that such Awards may
not exceed the number of shares of Common Stock then  available  for award under
this Plan.

     Each Director Option shall, unless otherwise provided in the specific Award
granted,  have a term of ten years from the date of grant,  notwithstanding  any
earlier termination of the status of the holder as a Nonemployee  Director.  The
purchase price of each share of Common Stock subject to a Director  Option shall
be equal to the Fair Market Value of the Common Stock on the date of grant. Upon
a Change in Control,  all Director Options shall  immediately vest. All Director
Options held by a Nonemployee  Director shall vest upon such  Director's  death.
All unvested  Director  Options shall be forfeited if the  Nonemployee  Director
resigns as a Director without the consent of a majority of the other Directors.

     Any  Award of  Director  Options  shall be  embodied  in a  Director  Award
Agreement,  which shall contain the terms,  conditions  and  limitations  of the
Award,  including without  limitation those set forth above, and shall be signed
by the Participant to whom the Director Options are granted and by an Authorized
Officer for and on behalf of the Company. Without limiting the generality of any
other provision  hereof,  Director  Options in addition to those provided for in
the  first  paragraph  of this  subsection  may be  granted  by the Board or the
Committee  to a  Nonemployee  Director who serves as chairman or a member of the
Audit,  Compensation or Nominating  committees of the Board;  provided that each
such  non-chairman  member of any such committee to whom a Director Option is to
be granted is deemed by the  Committee to be  "independent"  for purposes of the
rules of The Nasdaq Stock Market, Inc.

     (b) Director  Restricted  Stock.  On the date of a  Nonemployee  Director's
first  appointment  or election to the Board of  Directors  and on or after each
Annual  Director Award Date, the Board or the Committee may, in its  discretion,
grant such Nonemployee  Director one or more Awards of Restricted Stock for such
number of shares of Restricted Stock as the Board or the Committee may determine
in its discretion, subject to the limitation that such Awards may not exceed the
number of shares of Common Stock then available for award under this Plan.

     Upon a Change in  Control,  all shares of Director  Restricted  Stock shall
immediately vest. All unvested  Restricted Stock held by a Nonemployee  Director
shall  vest  upon  such  Director's  death.  All  unvested  shares  of  Director
Restricted  Stock shall be forfeited if the  Nonemployee  Director  resigns as a
Director without the consent of a majority of the other Directors.

     Any Award of  Director  Restricted  Stock  shall be  embodied in a Director
Award  Agreement,  which shall contain the terms,  conditions and limitations of
the Award,  including  without  limitation  those set forth above,  and shall be
signed by the Participant to whom the Director  Restricted  Stock is granted and
by an Authorized Officer for and on behalf of the Company.  Without limiting the
generality of any other provision hereof, Awards of Restricted Stock in addition
to those provided for in the first  paragraph of this  subsection may be granted
by the Board or the Committee to a  Nonemployee  Director who serves as chairman
or a member of the Audit,  Compensation  or Nominating  committees of the Board;
provided  that each such  non-chairman  member of any such  committee to whom an
Award of  Restricted  Stock is to be  granted is deemed by the  Committee  to be
"independent" for purposes of the rules of The Nasdaq Stock Market, Inc."

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     The Company also does hereby amend and restate the  definition of "Director
Restricted  Stock" in Section 3 of the Plan,  effective as of May 10,  2005,  to
read in its entirety as follows:

     ""Director  Restricted Stock" means Restricted Stock granted to Nonemployee
Directors pursuant to Section 9 hereof."

     The  Company  also does hereby  amend and  restate  Section 19 of the Plan,
effective as of May 10, 2005, to read in its entirety as follows:

     "19.  Effectiveness.  The Plan was amended and restated  effective February
17, 2000 and subsequently amended by a First Amendment effective May 22, 2002, a
Second Amendment  effective  February 18, 2003, a Third Amendment  effective May
23,  2003,  a Fourth  Amendment  effective  May 21,  2004 and a Fifth  Amendment
effective May 10, 2005."


     IN WITNESS  WHEREOF,  this Amendment has been executed  effective as of May
10, 2005.

                                      CARRIZO OIL & GAS, INC.


                                      By: /s/ Paul F. Boling
                                          ------------------
                                      Name:  Paul F. Boling
                                      Title: Vice President,
                                             Chief Financial Officer,
                                             Secretary and Treasurer