SECURITIES AND EXCHANGE COMMISSION

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SCHEDULE TO

(Amendment No.   )

DIAMOND OFFSHORE DRILLING, INC.

DIAMOND OFFSHORE DRILLING, INC.
(Name of Filing Person (Offeror))

Zero Coupon Convertible Debentures due 2020
(Title of Class of Securities)

25271C AB 8
25271C AC 6
(CUSIP Numbers of Class of Securities)

William C. Long, Esq.
Diamond Offshore Drilling, Inc.
15415 Katy Freeway
Houston, Texas 77094
(281) 492-5300
(Name, Address and Telephone Number of Person Authorized to Receive Notices
and Communications on Behalf of Filing Persons)

Copies to:
Shelton M. Vaughan, Esq.
Duane Morris LLP
3200 Southwest Freeway, Suite 3150
Houston, Texas 77027
(713) 402-3900

CALCULATION OF FILING FEE

*	Calculated solely for purposes of determining the filing fee. The purchase price of the Zero Coupon Convertible Debentures due 2020, as described herein, is $594.25 per $1,000 principal amount at maturity outstanding. As of May 5, 2005, there was approximately $805,000,000.00 in aggregate principal amount at maturity outstanding, resulting in an aggregate maximum purchase price of $478,371,250.
**	The amount of the filing fee was calculated in accordance with Rule 0-11 of the Securities Exchange Act of 1934, as amended, and equals $117.70 for each $1,000,000 of the value of the transaction.

o	Check the box if any part of the fee is offset as provided by Rule 0-11(a)(2) and identify the filing with which the offsetting fee was previously paid. Identify the previous filing by registration statement number, or the Form or Schedule and the date of its filing.

o	Check the box if the filing relates solely to preliminary communications made before the commencement of a tender offer. Check the appropriate boxes to designate any transactions to which this statement relates:

Check the following box if the filing is a final amendment reporting the results of the tender offer. o

 

TABLE OF CONTENTS

INTRODUCTORY STATEMENT
	Items 1 through 9
	Item 10. Financial Statements
	Item 11. Additional Information
	Item 12. Exhibits
	Item 13. Information Required by Schedule 13E-3
SIGNATURE
EXHIBIT INDEX
Company Notice to Holders
Form of Purchase Notice
Form of Notice of Withdrawal
Substitute Form W-9
Guidelines for Certification of TIN

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Table of Contents

INTRODUCTORY STATEMENT

     This Tender Offer Statement on Schedule TO-I (“Schedule TO-I”) is filed by Diamond Offshore Drilling, Inc., a Delaware corporation (the “Company”), and relates to the offer to purchase the Zero Coupon Convertible Debentures due 2020 issued by the Company on June 6, 2000 (the “Securities”), upon the terms and subject to the conditions set forth in the Indenture (as defined below), the Company Notice, dated May 6, 2005 (the “Company Notice”), and the related offer materials filed as Exhibits (a)(1)(B) to (d)(4) to this Schedule TO-I (which Company Notice and related offer materials, as amended or supplemented from time to time, collectively constitute the “Option”). The Securities were issued pursuant to an Indenture, dated as of February 4, 1997, between the Company and JPMorgan Chase Bank, N.A. (formerly known as The Chase Manhattan Bank), as Trustee (“Trustee”), as amended by the Second Supplemental Indenture, dated as of June 6, 2000, between the Company and the Trustee (the “Indenture”).

     The Option will expire at 5:00 p.m., New York City time, on June 6, 2005. This Schedule TO-I is intended to satisfy the disclosure requirements of Rule 13e-4(c)(2) under the Securities Exchange Act of 1934, as amended (the “Exchange Act”).

Items 1 through 9.

     The Company is the issuer of the Securities and is offering to purchase all of the Securities pursuant to the terms of the Indenture. The Securities are convertible into shares of common stock, par value $0.01 per share, of the Company. The Company maintains its principal executive offices at 15415 Katy Freeway, Houston, Texas 77094. The telephone number there is (281) 492-5300. As permitted by General Instruction F to Schedule TO, all of the information set forth in the Option is incorporated by reference into this Schedule TO-I.

Item 10. Financial Statements.

     (a) The Company believes that its financial condition is not material to a securityholder’s decision whether to put the Securities to the Company because the consideration being paid to holders surrendering Securities consists solely of cash, the Option is not subject to any financing conditions, the Option applies to all outstanding Securities and the Company is a public reporting company that files reports electronically on EDGAR. The financial condition and results of operations of the Company and its subsidiaries are reported electronically on EDGAR on a consolidated basis.

     (b) Not applicable.

Item 11. Additional Information.

     (a) Not applicable.

     (b) Not applicable.

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Item 12. Exhibits

Item 13. Information Required by Schedule 13E-3

     Not applicable.

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SIGNATURE

     After due inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

	DIAMOND OFFSHORE DRILLING, INC.
	By:	/s/ William C. Long
		Name:	William C. Long
		Title:	Vice President, General Counsel and Secretary

Dated: May 6, 2005

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EXHIBIT INDEX

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