October 29, 2008

Carrizo Oil & Gas, Inc. Announces Credit Facility Availability is Increased By $57.5 Million to $222.5 Million

HOUSTON, Oct. 29 /PRNewswire-FirstCall/ -- Carrizo Oil & Gas, Inc. today announced the completion of a redetermination of the borrowing base for its credit facility. A consortium of six banks has agreed to increase the availability under the Company's credit facility by $57.5 million, or 35%, to $222.5 million. Carrizo currently has $120 million drawn and outstanding under the credit facility. Chief Executive Officer S. P. "Chip" Johnson, IV stated, "Carrizo's drilling success in the Barnett Shale and the reserves associated with these wells allowed our banks to significantly raise our borrowing base availability. With our 2009 Barnett Shale development plan expected to be largely funded out of cash flow, this increase in credit will improve our financial flexibility."

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Carrizo's next credit facility redetermination is scheduled in the first quarter of 2009. The Company expects the growth in reserves and new production resulting from the Company's fourth quarter Barnett development activity should have a favorable impact on this redetermination.

About the Company

Carrizo Oil & Gas, Inc. is a Houston-based energy company actively engaged in the exploration, development, exploitation, and production of oil and natural gas primarily in the Barnett Shale in North Texas and in proven onshore trends along the Texas and Louisiana Gulf Coast regions. Carrizo controls significant prospective acreage blocks and utilizes advanced 3-D seismic techniques to identify potential oil and gas reserves and drilling opportunities.

Statements in this news release that are not historical facts, including those related to funding of development plans, financial flexibility, growth in reserves, new production and future borrowing base levels, are forward-looking statements that are based on current expectations. Although Carrizo believes that its expectations are based on reasonable assumptions, it can give no assurance that these expectations will prove correct. Important factors that could cause actual results to differ materially from those in the forward-looking statements include market and other conditions, capital needs and uses, commodity price changes, effects of the global financial crisis on exploration activity and other risks described in Carrizo's Form 10-K for the year ended December 31, 2007 and its other filings with the Securities and Exchange Commission.

    Contact:  Carrizo Oil & Gas, Inc.              Richard Hunter, Vice President of Investor Relations              B. Allen Connell, Consultant              Paul F. Boling, Chief Financial Officer              (713) 328-1000  

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Carrizo Oil & Gas, Inc.

CONTACT: Richard Hunter, Vice President of Investor Relations, B. AllenConnell, Consultant, or Paul F. Boling, Chief Financial Officer, all ofCarrizo Oil & Gas, Inc., +1-713-328-1000