PRESS RELEASE      Contact:     Carrizo Oil & Gas, Inc.
                                B. Allen Connell, Director of Investor Relations
                                Paul F. Boling, Chief Financial Officer
                                (281) 496-1352

CARRIZO OIL & GAS,  INC.  ANNOUNCES  FIRST  QUARTER 2004  FINANCIAL  RESULTS AND
RECORD REVENUES

HOUSTON,  May 13, 2004-- Carrizo Oil & Gas, Inc.  (Nasdaq:  CRZO) today reported
the Company's  financial  results for the first quarter of 2004,  which included
the following highlights:

o   Production of 1.86 Bcfe.

o   Record quarterly revenue of $10.9 million.

o   Net Income of $2.0 million.

o   EBITDA of $7.1 million.

Revenues  for the three  months  ended  March 31,  2004 were  $10.9  million  as
compared to $10.7 million  during the quarter ended March 31, 2003. The increase
in revenues was driven by higher prevailing oil and natural gas prices partially
offset by lower  production.  Production  volumes  during the three months ended
March 31, 2004 were 1.86 Bcfe as compared to 1.94 Bcfe during the first  quarter
of 2003.  Carrizo's  average oil sales price  increased 12 percent to $33.33 per
barrel  from  $29.74 per  barrel  during  the first  quarter of 2003,  while the
average  natural gas sales price was  virtually  unchanged at $5.95  compared to
$5.91 per Mcf in the first  quarter of 2003.  The above prices  include the cash
effect of hedging activities.

After  dividends,  accretion of discount on preferred  stock and the  cumulative
effect of change in accounting principle, the Company reported net income change
in accounting principle available to common shares of $2.0 million, or $0.12 and
$0.10 per basic and diluted  share,  respectively,  for the three  months  ended
March 31, 2004,  as compared to $2.7  million,  or $0.19 and $0.16 per basic and
diluted share, respectively, for the same quarter during 2003.

EBITDA  (earnings  before  interest,  income tax,  depreciation and amortization
expenses, and certain other non-cash items) during the first quarter of 2004 was
$7.1 million, or $0.43 and $0.37 per basic and diluted share,  respectively,  as
compared  to $7.5  million,  or $0.53 and $0.43  per  basic and  diluted  share,
respectively, during the first quarter of 2003.

Oil and gas operating  expenses,  including  production taxes, were unchanged at
$1.7  million  during the three  months  ended March 31, 2004 as compared to the
first quarter of 2003 and the fourth quarter of 2003.



Depreciation,  depletion and  amortization  expenses  ("DD&A") were $3.2 million
during the three  months  ended  March 31,  2004 ($1.74 per Mcfe) as compared to
$3.0 million  ($1.57 per Mcfe) during the first quarter of 2003. The increase in
DD&A expense was due to an increase in the DD&A rate  primarily due to additions
to the proved property cost base.

General and administrative expenses ("G&A") increased to $2.1 million during the
three months  ended March 31, 2004 from $1.4 million  during the same quarter of
2003.  The increase in G&A was due  primarily to higher  incentive  compensation
costs and higher professional fees in connection with the 2003 year-end audit.

"We are very  pleased  with our first  quarter  financial  results and  drilling
success",  commented S.P.  Johnson IV,  Carrizo's  President and Chief Executive
Officer. "This high level of EBITDA,  combined with the proceeds from our recent
equity offering allows us to increase our working  interest in a very successful
drilling  program at high commodity  prices and relatively low service costs. We
remain on track with reaching our drilling  targets this year,  with seven wells
currently drilling in our core Gulf Coast region."

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 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,  including but not limited to those relating to
the  Company's  or  management's  intentions,   beliefs,  expectations,   hopes,
projections,  assessment of risks,  estimations,  plans or  predictions  for the
future  including  potential  effects or timing,  cash flow,  reserve growth and
shareholder value, the expected timing of drilling of additional wells 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, 2003 and its other filings with the Securities and Exchange Commission.

                        (Financial Highlights to Follow)



                             CARRIZO OIL & GAS, INC.
                            STATEMENTS OF OPERATIONS
                                   (unaudited)




                                                                                         THREE MONTHS ENDED
                                                                                            MARCH 31,
                                                                                ---------------------------------
                                                                                      2004             2003
                                                                                ---------------   ---------------
                                                                                            
Oil and natural gas revenues                                                     $  10,873,404     $  10,663,453
                                                                                ---------------   ---------------

Costs and expenses:
   Oil and natural gas operating expenses                                            1,676,209         1,719,811
   Depreciation, depletion and amortization                                          3,246,596         3,035,886
   General and administrative expenses                                               2,132,508         1,382,671
   Accretion expense related to asset retirement obligations                             6,442             8,001
   Stock option compensation expense (benefit)                                           9,682            (9,480)
                                                                                ---------------   ---------------

Total costs and expenses                                                             7,071,437         6,136,889
                                                                                ---------------   ---------------


Operating income                                                                     3,801,967         4,526,564
                                                                                ---------------   ---------------

Equity in loss of Pinnacle Gas Resources, Inc.                                        (243,785)                -
Other income and expenses, net                                                           9,005            99,914
Interest income                                                                         12,780            17,743
Interest expense, net of amounts capitalized                                           (43,397)           (4,963)
                                                                                ---------------   ---------------

Income before income taxes                                                           3,536,570         4,639,258
                                                                                ---------------   ---------------

Income tax expense                                                                   1,353,148         1,668,740
                                                                                ---------------   ---------------

Net income before cumulative effect of change in accounting principle                2,183,422         2,970,518
                                                                                ---------------   ---------------

Dividends and accretion of discount on preferred stock                                 197,995           181,045
                                                                                ---------------   ---------------

Net income available to common shares before cumulative effect of
  change in accounting principle                                                     1,985,427         2,789,473
                                                                                ---------------   ---------------

Cumulative effect of change in accounting principle                                          -           128,374
                                                                                ---------------   ---------------

Net income available to common shares                                            $   1,985,427     $   2,661,099
                                                                                ===============   ===============

EBITDA (see table below)                                                         $   7,064,010     $   7,541,991
                                                                                ===============   ===============

Basic net income per common share:
  Net income before cumulative effect of change in accounting principle          $        0.12     $        0.20
  Cumulative effect of change in accounting principle                                     0.00             (0.01)
                                                                                ---------------   ---------------

  Basic net income per common share                                              $        0.12     $        0.19
                                                                                ===============   ===============

Diluted net income per common share:
  Net income before cumulative effect of change in accounting principle          $        0.10     $        0.17
  Cumulative effect of change in accounting principle                                     0.00             (0.01)
                                                                                ---------------   ---------------

Diluted net income per common share                                              $        0.10     $        0.16
                                                                                ===============   ===============

Basic weighted average common shares outstanding                                    16,613,430        14,198,134
                                                                                ---------------   ---------------

Diluted weighted average common shares outstanding                                  19,284,153        17,456,766
                                                                                ---------------   ---------------


                                     (more)



                 CARRIZO OIL & GAS, INC.
                 CONDENSED BALANCE SHEET






                                                                                    03/31/04         12/31/03
                                                                                ---------------   ---------------
                                                                                           (unaudited)
                                                                                            
ASSETS:
  Cash and cash equivalents                                                      $   4,892,495     $   3,322,057
  Other current assets                                                              10,729,039        11,003,512
  Net property and equipment                                                       153,723,334       135,273,200
  Other assets                                                                         527,930           567,755
  Investment in Pinnacle Gas Resources, Inc.                                         6,384,592         6,636,589
                                                                                ---------------   ---------------

TOTAL ASSETS                                                                     $ 176,257,390     $ 156,803,113
                                                                                ===============   ===============

LIABILITIES AND EQUITY:
  Accounts payable and accrued liabilities                                       $  24,349,870     $  24,001,971
  Current maturities of long-term debt                                               1,358,519         2,139,549
  Long-term notes payable                                                               97,310         7,121,646
  Long-term subordinated notes payable                                              27,381,964        26,991,413
  Deferred income taxes                                                             13,787,701        12,479,553
  Other liabilities                                                                    905,506           883,117
  Convertible participating preferred stock                                          7,312,098         7,114,103
  Equity                                                                           101,064,422        76,071,761
                                                                                ---------------   ---------------

TOTAL LIABILITIES AND EQUITY                                                     $ 176,257,390     $ 156,803,113
                                                                                ===============   ===============


(1)  Income tax expense  for the three  months  ended March 31, 2004  includes a
     $1,308,148  provision for deferred income taxes and a $45,000 provision for
     currently payable franchise taxes.  Income tax expense for the three months
     ended March 31, 2003 includes a $1,623,740  provision  for deferred  income
     taxes and a $45,000 provision for currently payable franchise taxes.

(2)  Long-term  notes  payable  at  December  31,  2003  includes  a note in the
     principal amount $863,246 payable by CCBM, Inc. (a wholly-owned  subsidiary
     of the Company) to Rocky Mountain Gas, Inc. recourse solely to CCBM, Inc.'s
     interests in certain  undeveloped oil and natural gas leases in Wyoming and
     Montana.  At March 31, 2004 and  December 31, 2003  current  maturities  of
     long-term debt include $704,832 and $863,246, respectively,  related to the
     CCBM, Inc. note.

(3)  Subordinated  notes  payable are presented net of discounts of $320,463 and
     $342,012 as of March 31, 2004 and December 31, 2003, respectively.

(4)  Stock option compensation  expense (benefit) is a non-cash charge (benefit)
     resulting  from the  change in the price of the stock  underlying  employee
     stock options that were repriced in February 2000.

(5)  In  February  2002,  the  Company  consummated  the sale of $6  million  of
     convertible  participating  preferred  stock and  warrants to purchase  the
     Company's  common stock.  Convertible  preferred  stock is presented net of
     discounts.

(6)  The Company  adopted  Financial  Accounting  Standards  Board  Statement of
     Financial  Accounting  Standards  ("SFAS") No. 143,  "Accounting  for Asset
     Retirement  Obligations"  on  January  1,  2003,  resulting  in a charge of
     $128,374  for the quarter  ended  March 31,  2003 to record the  cumulative
     effect of the change in accounting principle. (more)



                             CARRIZO OIL & GAS, INC.
                              NON-GAAP DISCLOSURES
                                   (unaudited)




                                                                                      THREE MONTHS ENDED
                                                                                            MARCH 31,
                                                                                ---------------------------------
Reconciliation of Net Income to EBITDA                                               2004              2003
- ---------------------------------------------------------------------           ---------------   ---------------
                                                                                             
Net income before cumulative effect of change in accounting principle            $   2,183,422     $   2,970,518
                                                                                ---------------   ---------------

Cumulative effect of change in accounting principle                                          -           128,374
                                                                                ---------------   ---------------

Net Income                                                                       $   2,183,422     $   2,842,144
                                                                                ---------------   ---------------

Adjustments:
  Depreciation, depletion and amortization                                           3,246,596         3,035,886
  Interest expense, net of amounts capitalized and interest income                      30,617           (12,780)
  Income taxes                                                                       1,353,148         1,668,740
  Equity in Pinnacle Gas Resources, Inc.                                               243,785                 -
  Accretion expense related to asset retirement obligations                              6,442             8,001
                                                                                ---------------   ---------------

EBITDA, as defined                                                               $   7,064,010     $   7,541,991
                                                                                ===============   ===============

EBITDA per basic common share                                                    $        0.43     $        0.53
                                                                                ===============   ===============

EBITDA per diluted common share                                                  $        0.37     $        0.43
                                                                                ===============   ===============


                           OTHER FINANCIAL DISCLOSURES
                                   (unaudited)



                              Operating Cash Flow
- -----------------------------------------------------------------------------------------------------------------
                                                                                            
Operating Cash Flow                                                              $   6,321,269     $   6,881,626
                                                                                ===============   ===============

Operating Cash Flow per basic common share                                       $        0.38     $        0.48
                                                                                ===============   ===============

Operating Cash Flow per diluted common share                                     $        0.33     $        0.39
                                                                                ===============   ===============



                          PRODUCTION VOLUMES AND PRICES
                                   (unaudited)



Production volumes-

                                                                                            
    Oil and condensate (Bbls)                                                           87,123           139,070
    Natural gas (Mcf)                                                                1,338,776         1,103,602
    Natural gas equivalent (Mcfe)                                                    1,861,514         1,938,022

Average sales prices-

    Oil and condensate (per Bbl)                                                        $33.33     $       29.74
    Natural gas (per Mcf)                                                        $        5.95     $        5.91
    Natural gas equivalent (per Mcfe)                                            $        5.84     $        5.50



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