PRESS RELEASE          CONTACT: CARRIZO OIL & GAS, INC.
                                B. ALLEN CONNELL, DIRECTOR OF INVESTOR RELATIONS
                                FRANK A. WOJTEK, CHIEF FINANCIAL OFFICER
                                (281) 496-1352

CARRIZO OIL & GAS, INC. UPDATES FIRST QUARTER 2003 OPERATIONS; PRODUCTION LEVELS
INCREASE 37 PERCENT OVER PRIOR YEAR; ANOTHER SUCCESSFUL OFFSET WELL DRILLED IN
PROVIDENCE FIELD IN MATAGORDA COUNTY

HOUSTON, APRIL 24, 2003 - CARRIZO OIL & GAS, INC. (NASDAQ: CRZO) today announced
the operating results for the first quarter of 2003. In the Company's core areas
in South Texas and Louisiana, the Company participated in the drilling of four
gross exploratory wells, two of which were successful. Since March 31, 2003,
four additional gross wells have reached total depth, all of which were
successful, resulting in a 75 percent apparent success rate year-to-date. As of
the end of the quarter, the two successful wells drilled in the first quarter
and one additional well drilled in the fourth quarter 2002 were in process of
being completed, or were awaiting pipeline hookup to commence production, and
drilling operations were underway on three additional wells.

Production during the first quarter of 2003 was estimated at 1.94 Bcfe, 37
percent higher than first quarter 2002. Approximately 57 percent of production
was natural gas. The Company estimates that first quarter 2003 sales prices,
including the effect of hedging activities, averaged approximately $5.99 per Mcf
and $29.32 per barrel, which should result in record revenues for the quarter.
The natural gas sales price was negatively affected $0.63 per Mcf and the oil
sales price was negatively affected $3.64 per barrel by hedging activities. The
oil sales price reflects the large volume of condensate production relative to
total oil production. The average gas price reflects lower prices received for
the Company's coalbed methane production in Wyoming, which averaged 479 Mcf per
day and a sales price of $3.34 per Mcf during the quarter.

Operating highlights during the first quarter of 2003 included the following:

     o    The Company continued its successful exploratory drilling program in
          the Matagorda Project Area in Matagorda County, Texas. In January
          2003, the fourth successful well drilled in the Providence Field, the
          "Matthes-Huebner #1", commenced production at a gross rate of
          approximately 2,518 barrels of oil and 7,700 Mcf of gas (22,800 Mcfe)
          per day. Carrizo owns a 32.2125 percent before payout working interest
          in the well. Gross production from the four producing wells in the
          field averaged approximately 5,300 barrels of oil and 17,250 Mcf of
          gas (49,000 Mcfe) per day during the first quarter of 2003, or
          approximately 12,000 Mcfe per day net to Carrizo's interest.

          On March 9 and March 11, 2003, the Company, as operator, spud the
          "Pauline-Huebner A-382 #2" and "Pauline-Huebner A-382 #3" wells,
          respectively. The Pauline-Huebner A-382 #2 well targeted previously
          untested potential pay horizons structurally downthrown to the
          Providence Field and reached total depth of 12,500 feet on April 7,
          2003. The well logs indicate approximately 74 feet of apparent net pay
          in three potential pay intervals. The Company's working interest
          ranges from 46.5 to 52.5 percent in the primary well objectives,
          depending upon the actual depth of the zone to be produced. The
          Company has completed the construction


          of the production facilities and expects to begin perforating and
          testing the well by the end of this week. The Pauline-Huebner A-382 #3
          well was drilled as an offset well to the Matthes-Huebner #1 in the
          Providence Field and reached total depth on April 20, 2003. The well
          logs indicate approximately 57 feet of apparent net pay in two
          potential pay intervals. Carrizo owns a 39.75 percent working interest
          in the well. Completion operations are underway and the Company
          expects to be able to test the well in the next seven to ten days.

          On April 15, 2003, the Company, as operator, spud an additional 12,550
          foot test well in the Project Area, targeting another untested
          downthrown structure believed to be along the same major fault as the
          Pauline-Huebner A-382 #2 well.

     o    In the Liberty Project Area in Liberty County, Texas, the Company
          resolved the remaining issues relating to the connection of the
          Hankamer #1 well to pipeline infrastructure and the well commenced
          production in early April from the Cook Mountain interval at a rate of
          525 barrels of oil and 7,000 Mcf of gas (10,150 Mcfe) per day. Carrizo
          is the operator of the well and owns a 40 percent working interest.

          On April 21, 2003, the Company, as operator, spud an additional 10,500
          foot test well in the Project Area that also targets the Cook Mountain
          interval.

"Although our 2003 drilling program got off to a somewhat slower pace than we
would have liked, we were able to accelerate the pace later in the quarter with
the simultaneous drilling of our two latest successful wells in Matagorda
County", commented S.P. Johnson IV, Carrizo's President and Chief Executive
Officer. "We expect to test both of these wells shortly and expect to be able to
put both of these wells on production by early May. Based upon the well logs, we
anticipate that the wells should exhibit flow rate characteristics similar to
our other recent high rate wells in the area, thus significantly impacting
anticipated second quarter 2003 production levels. Carrizo currently has two
rigs drilling in Liberty and Matagorda Counties and we expect to spud two
additional wells shortly, including a 13,500 foot Wilcox test well in Live Oak
County, Texas."

Carrizo Oil & Gas, Inc., is a Houston-based energy company engaged in the
exploration, development, exploitation and production of oil and natural gas in
proven onshore trends primarily 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, including but not limited to those relating to
the results, potential effects, risk profiles, schedule, prospects or estimates
for current or future drilling or wells, expected timing of completing and
testing the Pauline-Huebner A-382 #2 and #3 wells, the number of potential pay
zones in the wells, anticipated flow rates and the timing of commencement of
production from these wells, the impact of such wells on anticipated second
quarter production levels, expected timing of spudding or drilling additional
wells, potential success of wells believed to be located along certain faults
and other statements that are not historical facts are forward looking
statements that are based on current expectations. Although the Company 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 the results and dependence on exploratory drilling
activities, operating risks, oil and gas price levels, land issues, availability
of equipment, weather and other risks described in the Company's Form 10-K for
the year ended December 31, 2002 and its other filings with the Securities and
Exchange Commission.