Exhibit 99.1

FOR IMMEDIATE RELEASE		CONTACT: Darren Daugherty
		Director, Investor Relations
		(281) 492-5370

DIAMOND OFFSHORE ANNOUNCES
THIRD QUARTER 2011 RESULTS

Houston, Texas, October 20, 2011 — Diamond Offshore Drilling, Inc. (NYSE:DO) today reported net income for the third quarter of 2011 of $256.9 million, or $1.85 per share on a diluted basis, compared with net income of $198.5 million, or $1.43 per share on a diluted basis, in the same period a year earlier. Revenues in the third quarter of 2011 were $878.2 million, compared with revenues of $799.7 million in the third quarter of 2010.

“We are pleased with our third quarter results, which reflect continued strength in the market,” said Larry Dickerson, President and Chief Executive Officer of Diamond Offshore. “Since the second quarter, we added 14 new contracts, totaling 18 rig years or $1.4 billion of revenue backlog.”

“We continue to execute on initiatives to contain operating costs and minimize unplanned rig repair downtime,” said Dickerson. “Additionally, results benefited from revenues related to the mobilization of a rig from Brazil to the Gulf of Mexico and a shift of some planned downtime into the fourth quarter.”

CONFERENCE CALL

Diamond Offshore will host a conference call to discuss third quarter results on Thursday, October 20, 2011 beginning at 9:00 a.m. Central Daylight Time. A live webcast of the call will be available online on our Company’s website, www.diamondoffshore.com. Those interested in participating in the question and answer session should dial 800-247-9979, or for international callers, 973-321-1100. The conference ID number is 13267272. An online replay will also be available on www.diamondoffshore.com following the call.

ABOUT DIAMOND OFFSHORE

Diamond Offshore provides contract drilling services to the energy industry and is a leader in deepwater drilling. Additional information on Diamond Offshore and access to the Company’s SEC filings is available on the Internet at www.diamondoffshore.com.

FORWARD-LOOKING STATEMENTS

Statements contained in this press release which are not historical facts are “forward-looking statements” within the meaning of the federal securities laws. Forward-looking statements are inherently uncertain and subject to a variety of risks that could cause actual results to differ materially from those expected by management of the Company. A discussion of the important risk factors and other considerations that could materially impact these matters as well as the Company’s overall business and financial performance can be found in the Company’s reports filed with the Securities and Exchange Commission and readers of this release are urged to review those reports carefully when considering these forward-looking statements. Copies of these reports are available through the Company’s website www.diamondoffshore.com. Given these risk factors, investors and analysts should not place undue reliance on forward-looking statements. Any such forward-looking statements speak only as of the date of this press release. The Company expressly disclaims any obligation or undertaking to release publicly any updates or revisions to any forward-looking statement to reflect any change in the Company’s expectations with regard thereto or any change in events, conditions or circumstances on which any forward-looking statement is based.

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DIAMOND OFFSHORE DRILLING, INC. AND SUBSIDIARIES
CONSOLIDATED STATEMENTS OF OPERATIONS
(Unaudited)
(In thousands, except per share data)

		Three Months Ended								Nine Months Ended
		September 30,								September 30,
		2011				2010				2011				2010
Revenues:
Contract drilling		$	861,511			$	748,998			$	2,520,030			$	2,405,175
Revenues related to reimbursable expenses			16,666				50,726				54,032				76,833
Total revenues			878,177				799,724				2,574,062				2,482,008
Operating expenses:
Contract drilling, excluding depreciation			391,369				350,555				1,141,739				1,008,551
Reimbursable expenses			16,206				50,313				52,443				75,397
Depreciation			101,175				99,117				303,523				297,265
General and administrative			14,879				16,999				48,976				50,502
Bad debt expense (recovery)			4,734				(2,048	)			(5,413	)			(5,946	)
Gain on disposition of assets			(463	)			(32,392	)			(4,344	)			(33,425	)
Total operating expenses			527,900				482,544				1,536,924				1,392,344
Operating income			350,277				317,180				1,037,138				1,089,664
Other income (expense):
Interest income			2,024				395				3,565				2,154
Interest expense			(15,874	)			(22,567	)			(60,144	)			(66,221	)
Foreign currency transaction gain (loss)			(1,442	)			3,724				(4,603	)			194
Other, net			(136	)			(166	)			(232	)			(287	)
Income before income tax expense			334,849				298,566				975,724				1,025,504
Income tax expense			(77,995	)			(100,042	)			(201,672	)			(311,734	)
Net Income		$	256,854			$	198,524			$	774,052			$	713,770
Income per share:
Basic		$	1.85			$	1.43			$	5.57			$	5.13
Diluted		$	1.85			$	1.43			$	5.57			$	5.13
Weighted average shares outstanding:
Shares of common stock			139,027				139,027				139,027				139,026
Dilutive potential shares of common stock			14				10				21				55
Total weighted average shares outstanding			139,041				139,037				139,048				139,081

DIAMOND OFFSHORE DRILLING, INC. AND SUBSIDIARIES
RESULTS OF OPERATIONS
(Unaudited)
(In thousands)

		Three Months Ended
		September 30,
		2011				2010
REVENUES
High Specification Floaters		$	464,512			$	305,335
Intermediate Semisubmersibles			350,409				380,438
Jack-ups			46,540				63,133
Other			50				92
Total Contract Drilling Revenue		$	861,511			$	748,998
Revenues Related to Reimbursable Expenses		$	16,666			$	50,726
CONTRACT DRILLING EXPENSE
High Specification Floaters		$	188,071			$	148,503
Intermediate Semisubmersibles			153,416				154,731
Jack-ups			43,281				43,940
Other			6,601				3,381
Total Contract Drilling Expense		$	391,369			$	350,555
Reimbursable Expenses		$	16,206			$	50,313
OPERATING INCOME
High Specification Floaters		$	276,441			$	156,832
Intermediate Semisubmersibles			196,993				225,707
Jack-ups			3,259				19,193
Other			(6,551	)			(3,289	)
Reimbursable expenses, net			460				413
Depreciation			(101,175	)			(99,117	)
General and administrative expense			(14,879	)			(16,999	)
Bad debt (expense) recovery			(4,734	)			2,048
Gain on disposition of assets			463				32,392
Total Operating Income		$	350,277			$	317,180

DIAMOND OFFSHORE DRILLING, INC. AND SUBSIDIARIES
CONDENSED CONSOLIDATED BALANCE SHEETS
(In thousands)

		September 30,				December 31,
		2011				2010
		(unaudited)
ASSETS
Current assets:
Cash and cash equivalents		$	348,003			$	464,393
Marketable securities			801,931				612,346
Accounts receivable, net of allowance for bad debts			622,949				609,606
Prepaid expenses and other current assets			157,389				177,153
Total current assets			1,930,272				1,863,498
Drilling and other property and equipment, net of accumulated depreciation			4,605,748				4,283,792
Long-term receivable			—				35,361
Other assets			303,215				544,333
Total assets		$	6,839,235			$	6,726,984
LIABILITIES AND STOCKHOLDERS’ EQUITY
Current liabilities		$	372,961			$	626,288
Long-term debt			1,495,765				1,495,593
Deferred tax liability			519,980				542,258
Other liabilities			189,914				201,133
Stockholders’ equity			4,260,615				3,861,712
Total liabilities and stockholders’ equity		$	6,839,235			$	6,726,984

DIAMOND OFFSHORE DRILLING, INC. AND SUBSIDIARIES
AVERAGE DAYRATES AND UTILIZATION

		Third Quarter								Second Quarter								Third Quarter
		2011								2011								2010
		Dayrate				Utilization				Dayrate				Utilization				Dayrate				Utilization
		(Dayrate in thousands)
High Specification Floaters		$	380				93	%		$	364				94	%		$	364				56	%
Intermediate Semis		$	268				68	%		$	266				76	%		$	280				76	%
Jack-ups		$	84				44	%		$	82				60	%		$	82				60	%