IPAA 2004 Oil and Gas Investment Symposium April 2004 Nasdaq: CRZO Carrizo Oil & Gas, Inc.

2 Forward Looking Statements / Note Regarding Reserves Except for the historical information contained herein, the matters discussed in this presentation are forward looking statements that are based upon current expectations. Important factors that could cause actual results to differ materially from those in the forward looking statements include risks inherent in exploratory drilling activities, the timing and extent of changes in commodity prices, unforeseen engineering and mechanical or technological difficulties in drilling wells, availability of drilling rigs, availability of financing, land issues, federal and state regulatory developments and other risks more fully described in the Company’s S-2 Registration Statement and in the Company’s other filings with the Securities and Exchange Commission. Cautionary Note to U.S. Investors - The United States Securities and Exchange Commission permits oil and gas companies, in their filings with the SEC, to disclose only proved reserves that a company has demonstrated by actual production or conclusive formation tests to be economically and legally producible under existing economic and operating conditions. We use certain terms in this presentation such as “Unrisked Potential (Bcfe), Unrisked Upside (Bcfe), Unrisked Potential Net to CRZO’s W.I. (Bcfe), Exploration Potential Net to CRZO W.I., Formation Unrisked Potential Net to CRZO, Best Fit Potential Net to CRZO’s W.I.”, that the SEC’s guidelines strictly prohibit us from including in filings with the SEC. These terms include reserves with substantially less certainty, and no discount or other adjustment is included in the presentation of such reserve numbers. U.S. Investors are urged to consider closely the disclosure in our Form 10-K, File No , available from us at St. Mary’s Lane, Suite 800, Houston, Texas, and in our S-2 Registration Statement. You can also obtain these forms from the SEC by calling SEC-0330.

3 Reconciliation of Non-GAAP Financial Measures Reg. G -- Definition of EBITDA YEAR ENDED DECEMBER 31,

4 Company Profile Natural gas exploration – Onshore Gulf Coast Extensive 3-D seismic database for drill site generation Inventory of over 210 potential drill sites

5 Company Profile 81% drilling success on 78 gulf coast wells in last 3 years Record production and YE reserves for 2003 Recent equity offering allows higher working interest

6 Carrizo’s Operating Strategy Growth Through the Drillbit Focused exploration in proven, prolific Gulf Coast trends Utilize advanced 3-D seismic and interpretation techniques Generate and maintain 3-year drilling portfolio Control land and data for drill schedule optimization Maintain and incentivize a lean but premium team of geoscience, land, and operations personnel Apply exploration expertise to new areas with similar reservoir characteristics Diversify risk geologically and operationally

7 Capital Spending Strategy Since Inception

8 Company Overview

9 Investment Considerations nHighly attractive industry fundamentals nSignificant acceleration of our drilling activity in 2004 nConsistent successful results from proven technical team nEnormous land and seismic position nLarge number of internally generated drill sites nExposure to over 900 Bcfe net to Carrizo’s W.I. of unrisked exploration potential in Gulf Coast nSignificant additional option value in new opportunity areas nDoubled the public float to 12.3 mm shares

10 Offering Rationale Attractive Business Environment Commodity Prices Average Drilling Cost* * Land Rigs over 6,000 ft. Natural Gas Supply Electricity Generation Bcf/d

11 Gulf Coast Overview +Proven Track Record of Success +Over 6,658 Square Miles of 3D Seismic Data +Over 124 Leased Drillsites in Inventory +90 Additional Drilling Locations Identified Houston

Total Wells 20 75% 20 3D Seismic (Sq. Mi.) Encinitas 1997Total Wells 70 67% 90 3D Seismic 818 1,170 (Sq. Mi.) Total Wells 56 57% 146 3D Seismic 601 1,771 (Sq. Mi.)1998 Cobra 1999Total Wells 32 63% 178 3D Seismic 70 1,841 (Sq. Mi.) Total Wells 39 62% 217 3D Seismic 274 2,115 (Sq. Mi.) Total Wells 25 80% 242 3D Seismic 653 2,768 (Sq. Mi.) La Rose Providence Total Wells 20 85% 262 3D Seismic 2,659 5,427 (Sq. Mi.) Hankamer Total Wells % 295 3D Seismic1,230 6,658 (Sq. Mi.) Shadyside Espree Beach House2003 County / Parish 3D Seismic Discovery Dry Gulf Coast - Exploration Success Succ. Rate

13 Gulf Coast - Drilling Portfolio Drilling Locations (1) 36 (2) 68% 295$ % 72% 71% 72% Success Rate 523$ 13.6 South Louisiana 918$ 10.5 Southeast Texas 14204$ 35.5 Frio/ Vicksburg 850$ 26.1Wilcox Core AreasWells Drilled Capex (MM) (1) Approximately 89 additional locations being reviewed for future drilling. (2) Actual drilling capital expenditures are subject to change based on numerous factors as described in the prospectus. (3) 2004 Planned Capex includes $1.0 million for workovers and recompletions. Capex (3) (MM) $37.3 $ 8.9 $11.6 $ 9.8 $ 7.0 Planned

14 Houston S. E. Tx Wilcox Frio - Vickburg S. La. Gulf Coast - Area Diversification S. Louisiana S.E. Texas Frio/Vicksburg Wilcox Core Area 14 % 32 % 28 % 32 % Historical W.I. 52 % 41 % 43 % 52 % Target Avg. W.I. (‘04-’05)

15 Frio/Vicksburg Results Through > 144 / 204 Successful wells (71 %) > Reserves per well 0.4 to 9.0 Bcfe > Payout range: 2 to 24 months > Avg. Working interest of 32 % Providence Field ‘ MM/d per Well Encinitas Field ‘96 > 10 Locations Inventory > 35 identified prospects  2,102 miles of 3-D seismic > 14 wells / $ 11.6 m Capex in 2004 > Avg. Working Interest of 39 %

16 Southeast Texas Results Through > 13 / 18 Successful wells (72 %) > Reserves per well 0.5 to 8.0 Bcfe > Payout range: 3 to 18 months > Avg. Working interest of 28 % “Amplitude Anomalies” Espree #1 (‘03) mmcfe/d Beach House #1 (‘03) mmcfe/d Beach House #2 (‘03) mmcfe/d Inventory > 25 identified prospects > 900 miles of 3-D seismic > 9 Wells / $ 9.8 m Capex in 2004 > Avg. Working Interest of 41 %

17 Wilcox Results Through > 36 / 50 Successful wells (72 %) > Reserves per well 0.5 to 5.5 Bcfe > Payout range: 10 to 36 months > Avg. Working interest of 32 % Upper - Middle Wilcox Peal Ranch #1 (‘03) Peal Ranch #2 (‘03) Lower Wilcox Acre Plays >20 mmcfe/d Rates Upper Wilcox Weesatch Field (‘00) Inventory > 52 identified prospects > 1,793 miles of 3-D seismic > 8 Wells / $ 7.0 m Capex in 2004 > Avg. Working Interest of 50 %

18 South Louisiana Results Through > 8 / 23 Successful wells (35 %) 60% Since 2000 > Reserves per well 1.0 to 17.0 Bcfe > Payout range: 5 to 15 months > Avg. Working interest of 14 % La Rose Field (‘01) 15.6 mmcfe/d Shadyside #1 (‘03) 11.2 mmcfe/d Inventory > 11 identified prospects > 1,864 miles of 3-D seismic > 5 wells / $ 8.9 m Capex in 2004 > Avg. Working Interest of 50 % LL&E #1 (‘04) Drilling

Drilling Schedule Leased Drilling Locations 90 Additional Identified Opportunities

20 Summary Operating History ($ in Millions) Production: Mmcfe4,3116,6515,3927,2077,463 Mmcfe/d Revenue$ 10.2$ 26.8$ 26.2$ 26.8$ 38.5 EBITDA$ 4.9$ 19.6$ 21.1$ 18.1$ 25.7

21 Improved Liquidity 2004 CapEx $30 $45

22 Projected Capital Expenditures

23 Barnett Shale Industry n 700 MMCFD from 2,500 wells, (280 MCFD Average) n 6,000’ – 8,500’; $400 M- $1,750 M/well Carrizo n 7,500 net acres leased / 187 potential drillsites n 26 wells producing / 9 wells ready for pipeline connection n 2 MMCFD - Current net production

24 Parker/Tarrant/Denton County (Barnett Permits ) Parker Tarrant Wise Denton Carrizo Leases Ft. Worth

Carrizo Properties 22,000 net acres 30 wells CSFB $30 MM Private Equity Financing RMG Properties 22,000 net acres 30 wells Pinnacle Gas Resources, Inc. Coalbed Methane Development 63,000 Net Acres 155 Net Wells 1,000+ Potential Drill Sites Development capital in hand First Source Big Horn

26 North Sea Industry n Central North Sea: 62 MMBoe / success rate 25% n Southern North Sea: 73 Bcfe / success rate 22% Carrizo n 210,000 Acres under control in 7 blocks / 3D prospects identified n Commitment of $900M n Fundamentals are compelling (Similar to U.S. GOM in 1990’s)

27 Components of Asset Value Proved Reserves Gulf Coast Potential Unevaluated Seismic Data Ownership of Pinnacle Barnett Shale Opportunity Option Value in the North Sea

28 Key Points Focused Exploration Company Growth Through the Drillbit Production Growth 15 % CAGR Sustained Exploration Success Rate >80% Internally Generated Portfolio of 124 Leased Drillsites Incremental Option Value in New Opportunity Areas Increasing Working Interest in Existing Portfolio