NINTH AMENDMENT TO CREDIT AGREEMENT

NINTH AMENDMENT TO CREDIT AGREEMENT (this “ Amendment ”) dated as of April 30, 2009, by and among CARRIZO OIL & GAS, INC., a Texas corporation (“ Borrower ”), certain SUBSIDIARIES OF BORROWER, as Guarantors (in such capacity, “ Guarantors ”), the LENDERS party hereto (the “ Lenders ”), and GUARANTY BANK, as administrative agent for the Lenders (in such capacity, the “ Administrative Agent ”).  Unless otherwise expressly defined herein, capitalized terms used but not defined in this Amendment have the meanings assigned to such terms in the Credit Agreement (as defined below).

WHEREAS, Borrower, Guarantors, the Administrative Agent and certain Lenders have entered into that certain Credit Agreement, dated as of May 25, 2006 (as the same has been and may hereafter be amended, restated, supplemented or otherwise modified from time to time, the “ Credit Agreement ”); and

WHEREAS, Borrower has requested that the Administrative Agent and the Lenders (a) increase the Borrowing Base and (b) amend the Credit Agreement (i) to increase the Aggregate Commitment, and (ii) for certain other purposes as provided herein; and

WHEREAS, the Administrative Agent and the Lenders have agreed to (a) increase the Borrowing Base and (b) amend the Credit Agreement as provided herein, in each case, upon the terms and conditions set forth herein.

NOW, THEREFORE, for and in consideration of the mutual covenants and agreements herein contained and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged and confessed, the parties hereto hereby agree as follows:

SECTION 1.   Amendments to Credit Agreement.   Subject to the satisfaction or waiver in writing of each condition precedent set forth in Section 4 of this Amendment, and in reliance on the representations, warranties, covenants and agreements contained in this Amendment, the Credit Agreement shall be amended in the manner provided in this Section 1 .

1.1   Additional Definitions.   The following definitions shall be and they hereby are added to Section 1.01 of the Credit Agreement in appropriate alphabetical order:

“ Ninth Amendment Effective Date ” means April 30, 2009.

1.2   Amended Definition.   The following definition in Section 1.01 of the Credit Agreement shall be and it hereby is amended in its entirety to read as follows:

“ Aggregate Commitment ” means, as of the Ninth Amendment Effective Date, $255,000,000 and thereafter as such amount may be reduced or increased from time to time pursuant to Section 2.02 and Section 2.02A and as a result of changes in the Borrowing Base; provided that such amount shall not at any time exceed the lesser of (i) the Maximum Facility Amount and (ii) the Borrowing Base then in effect .   If at any time the Borrowing Base is reduced below the Aggregate

Commitment, the Aggregate Commitment shall be reduced automatically to the amount of the Borrowing Base in effect at such time.

1.3   Reserve Report; Proposed Borrowing Base.   Section 3.01 of the Credit Agreement shall be and it hereby is amended in its entirety to read as follows:

Section 3.01.   Reserve Report; Proposed Borrowing Base .  During the period from the Ninth Amendment Effective Date until the first Redetermination after the Ninth Amendment Effective Date, the Borrowing Base shall be $290,000,000.  As soon as available and in any event by February 28 and August 31 of each year, beginning August 31, 2009, the Borrower shall deliver to the Administrative Agent and each Lender a Reserve Report, prepared as of the immediately preceding December 31 and June 30, respectively, in form and substance reasonably satisfactory to the Administrative Agent and prepared by an Approved Petroleum Engineer (or, in the case of any Reserve Report other than the Reserve Report due on February 28 of each year, by petroleum engineers employed by the Borrower or its Subsidiaries or an Approved Petroleum Engineer) together with such other information, reports and data concerning the value of the Borrowing Base Properties as the Administrative Agent shall deem reasonably necessary to determine the value of such Borrowing Base Properties.  Simultaneously with the delivery to the Administrative Agent and the Lenders of each Reserve Report, the Borrower shall submit to the Administrative Agent and each Lender the Borrower’s requested amount of the Borrowing Base as of the next Redetermination Date.  Promptly after the receipt by the Administrative Agent of such Reserve Report and Borrower’s requested amount for the Borrowing Base, the Administrative Agent shall submit to the Lenders a recommended amount of the Borrowing Base and, with respect to any Redetermination prior to the Conforming Date, the Conforming Borrowing Base as of the next Redetermination Date; provided that no Redetermination of the Conforming Borrowing Base shall be required on or after the Conforming Date.

1.4   Capitalization.   Section 4.13 of the Credit Agreement shall be and it hereby is amended by deleting the phrase “Seventh Amendment Effective Date” located therein and substituting in lieu thereof the phrase “Ninth Amendment Effective Date”.

1.5   Restricted Subsidiaries.   Section 6.13 of the Credit Agreement shall be and it hereby is amended by deleting the phrase “Seventh Amendment Effective Date” located in clause (a) therein and substituting in lieu thereof the phrase “Ninth Amendment Effective Date”.

1.6   Waivers; Amendments.   Clause (b) of Section 11.02(b) of the Credit Agreement shall be and it hereby is amended in its entirety to read as follows:

(b)           Neither this Agreement nor any provision hereof may be waived, amended or modified except pursuant to an agreement or agreements in writing entered into by the Credit Parties and the Required Lenders or by the Credit Parties and the Administrative Agent with the consent of the Required Lenders; provided that no such agreement shall (1) increase the Borrowing Base or, at any

time prior to the Conforming Date, the Conforming Borrowing Base without the written consent of each Lender, (2) increase the Applicable Percentage or Commitment of any Lender without the written consent of such Lender, (3) increase the Maximum Facility Amount without the written consent of each Lender, (4) reduce the principal amount of any Loan or LC Disbursement or reduce the specified rate of interest thereon, or reduce any fees payable hereunder, without the written consent of each Lender affected thereby, (5) decrease the Monthly Reduction without the written consent of each Lender, (6) postpone the scheduled date of payment of the principal amount of any Loan or LC Disbursement, or any interest thereon, or any fees payable hereunder, or reduce the amount of, waive or excuse any such payment, or postpone the scheduled date of expiration of any of the Commitments, without the written consent of each Lender affected thereby, (7) change Section 2.17(b) or Section 2.17(c) in a manner that would alter the pro rata sharing of payments required thereby, without the written consent of each Lender, (8) except in connection with any sales, transfers, leases or other Dispositions permitted in Section 7.04, release any Credit Party from its obligations under the Loan Documents or release any of the Collateral, or (9) change any of the provisions of this Section or the definition of “Required Lenders” or any other provision hereof specifying the number or percentage of Lenders required to waive, amend or modify any rights hereunder or make any determination or grant any consent hereunder, without the written consent of each Lender; provided further that no such agreement shall amend, modify or otherwise affect the rights or duties of the Administrative Agent or the Issuing Bank hereunder without the prior written consent of the Administrative Agent or the Issuing Bank, as the case may be.  Notwithstanding anything to the contrary herein, no Defaulting Lender shall have any right to approve or disapprove any amendment, waiver or consent hereunder, except that the Commitment of such Lender may no