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Commission File Number 001-14273

(Exact name of Registrant as specified in its charter)

Registrant's telephone number, including area code: (31-20) 420-3191

Securities registered pursuant to Section 12(b) of the Act:

Securities registered pursuant to Section 12(g) of the Act: None

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes _X_ No __

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Exchange Act. Yes __ No _X_

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes_X_ No__

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K is not contained herein, and will not be contained, to the best of Registrant's knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K. _X_

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, or a non-accelerated filer. See definition of "accelerated filer and large accelerated filer" in Rule 12b-2 of the Exchange Act.

Large accelerated filer _X_ Accelerated filer ___ Non-accelerated filer ___

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes __ No _X_

As of June 30, 2005, the number of common shares outstanding was 26,097,353. At that date, the aggregate market value of common shares held by non-affiliates of the registrant was approximately $670,082,171.

As of February 22, 2006, the number of common shares outstanding was 25,833,963.

This Amendment No. 1 on Form 10-K/A amends Core Laboratories N.V.'s Annual Report on Form 10-K as of December 31, 2005, as filed by us on May 1, 2006, and is being filed to update the following information:

This amendment has no impact on our previously reported audited financial statements and notes thereto as of December 31, 2005. Furthermore, this Form 10-K/A does not reflect events occurring after the filing date of the original Form 10-K and does not modify or update the disclosures in that form in any way other than as explained above.

Set forth below as of April 15, 2006 are the names, ages and biographical information for our Supervisory Directors, including individuals who have been nominated for reelection at our 2006 Annual Shareholder meeting as a Supervisory Director.

Currently, our executive officers consist of David M. Demshur, Monty L. Davis, Richard L. Bergmark, and John D. Denson. Biographical information regarding Messrs. Demshur and Bergmark is set forth above. The following biographies describe the business experience of Messrs. Davis and Denson. Our executive officers are not Managing Directors of our Company for purposes of Dutch law.

Monty L. Davis, who is 51 years of age, joined Western Atlas International in 1977, holding various management positions including Atlas Wireline Division Financial Controller for Europe, Africa and the Middle East from 1983 to 1987, Core Laboratories Division Vice President of Finance from 1987 to 1991, and Atlas Wireline Division vice president of finance and administration from 1991 to 1993. In 1993, Mr. Davis left our Company and joined Bovar Inc. of Calgary, Canada, an environmental waste disposal company, as chief financial officer. From 1994 to 1995 he served as chief operating officer and from 1995 to 1998 he served as president and chief executive officer of Bovar Inc. Mr. Davis rejoined our Company as Senior Vice President in 1998, and in 1999 was promoted to Chief Operating Officer, the position he currently holds.

John D. Denson, who is 48 years of age, joined our Company in 1992 and has served as our Vice President, General Counsel and Secretary since 1994. Mr. Denson is a member of the State Bar of Texas.

The current members of the Audit Committee of our Supervisory Board are Messrs. Kearney (Chairman), Joyce and Perna. The Audit Committee's principal functions include making recommendations concerning the engagement of the independent accountants, reviewing with the independent accountants the plan and results of the auditing engagement, approving professional services provided by the independent accountants and reviewing the adequacy of our internal accounting controls. Each member of the Audit Committee is independent, as defined by Section 10A of the Exchange Act and by the corporate governance standards set forth by the NYSE and, to the extent consistent therewith, the Dutch Code. Each member of the Audit Committee is financially literate and Mr. Kearney qualifies as an audit committee financial expert under the rules promulgated pursuant to the Exchange Act.

Section 16(a) of the Exchange Act requires the Supervisory Directors, executive officers and persons who own more than ten percent of our common shares to file initial reports of ownership and reports of changes in ownership (Forms 3, 4 and 5) of our common shares with the Securities and Exchange Commission ("SEC") and the New York Stock Exchange ("NYSE"). Supervisory Directors, executive officers and greater than ten percent shareholders are required by SEC regulations to furnish us with copies of all such forms that they file.

To our knowledge, based solely upon our review of the Section 16(a) filings that have been received by us, we believe that during the fiscal year ending December 31, 2005, our Supervisory Directors, executive officers and ten percent shareholders complied with the applicable Section 16(a) filing requirements.

Each Supervisory Director who is not our full-time employee is paid:

We have not engaged in any transactions, or series of transactions, since the beginning of 2005 with our directors, executive officers, five percent beneficial owners or their immediate family members requiring disclosure.

Set forth below is a summary of the total fees paid to our registered independent public accounting firm, PricewaterhouseCoopers, for fiscal years 2005 and 2004. These fees consisted of:

Audit fees consist primarily of the audit and quarterly reviews of the consolidated financial statements, assistance with and review of documents filed with the SEC, work performed by tax professionals in connection with the audit and quarterly reviews, and the audit of internal controls in order to comply with the Sarbanes-Oxley Act of 2002.

Audit-related fees consist primarily of statutory audits of subsidiaries required by governmental or regulatory bodies and attestation services required by statute or regulation; audit of a benefit plan; and certain agreed-upon procedures including accounting and research work necessary to comply with generally accepted auditing standards.

Tax fees include professional services provided for preparation of federal and state tax returns, review of tax returns prepared by the Company, assistance in assembling data to respond to governmental reviews of past tax filings, and tax advice, exclusive of tax services rendered in connection with the audit.

Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, the Registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

I, David M. Demshur, certify that:

1. I have reviewed this Annual Report on Form 10-K/A of Core Laboratories N.V. (the "Registrant");

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

I, Richard L. Bergmark, certify that:

1. I have reviewed this Annual Report on Form 10-K/A of Core Laboratories N.V. (the "Registrant");

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;