8-A12G/A

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-A/A

(AMENDMENT NO. 1)

FOR REGISTRATION OF CERTAIN CLASSES OF SECURITIES

PURSUANT TO SECTION 12(b) OR (g) OF THE

SECURITIES EXCHANGE ACT OF 1934

NMT Medical, Inc.

(Exact Name of Registrant as Specified in Its Charter)

Delaware	95-4090463
(State of Incorporation or Organization)	(I.R.S. Employer Identification No.)
27 Wormwood Street Boston, Massachusetts	02210-1625
(Address of Principal Executive Offices)	(Zip Code)

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

Title of each class to be so registered	Name of each exchange on which each class to be so registered
Preferred Stock Purchase Rights	The NASDAQ Stock Market LLC

If this form relates to the registration of a class of securities pursuant to Section 12(b) of the Exchange Act and is effective pursuant to General Instruction A.(c), please check the following box.    x

If this form relates to the registration of a class of securities pursuant to Section 12(g) of the Exchange Act and is effective pursuant to General Instruction A.(d), please check the following box.    ¨

Securities Act registration statement file number to which this form relates (if applicable): Not applicable

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

Item 1. Description of Registrant’s Securities to be Registered.

NMT Medical, Inc. (the “Company”) hereby supplements Item 1 to reflect the following developments with respect to its Preferred Stock Purchase Rights:

As of December 14, 2006, the Company amended the Rights Agreement dated as of June 7, 1999 (the “Rights Agreement”), between the Company and American Stock Transfer & Trust Company, as Rights Agent, to delete the term “Exempted Person” and all references thereto, including, without limitation, all references to Whitney Equity Partners, L.P. and its affiliates.

The foregoing summary of the amendment to the Rights Agreement is qualified in its entirety by reference to the full text of the amendment, which is filed as Exhibit 1 hereto, and the full text of the Rights Agreement prior to the amendment, which is filed as Exhibit 1 to the Company’s Form 8-A, as filed with the Securities and Exchange Commission on June 8, 1999, each of which is incorporated herein by reference.

Item 2. Exhibits.

Exhibit No.	Description
1	Amendment to Rights Agreement, dated as of December 14, 2006, between the Company and American Stock Transfer & Trust Company.
2	Rights Agreement, dated as of June 7, 1999, between the Company and American Stock Transfer & Trust Company.(1)

(1) Incorporated by reference to Exhibits to the Registrant’s Current Report on Form 8-K, dated June 7, 1999 (File No. 000-21001).

SIGNATURE

Pursuant to the requirements of Section 12 of the Securities Exchange Act of 1934, the registrant has duly caused this amendment to the registration statement to be signed on its behalf by the undersigned, thereto duly authorized.

	NMT MEDICAL, INC.
Date: December 15, 2006	By:	/S/    RICHARD E. DAVIS
		Richard E. Davis Vice President and Chief Financial Officer

EXHIBIT INDEX

Exhibit No.	Description
1	Amendment to Rights Agreement, dated as of December 14, 2006, between NMT Medical, Inc. and American Stock Transfer & Trust Company.

EX-1

Exhibit 1

Execution Copy

AMENDMENT TO

RIGHTS AGREEMENT

This AMENDMENT, dated as of December 14, 2006 (the “Amendment”), amends the Rights Agreement, dated as of June 7, 1999 (the “Rights Agreement”), between NMT Medical, Inc. (formerly Nitinol Medical Technologies, Inc.), a Delaware corporation (the “Company”), and American Stock Transfer & Trust Company, a New York company, as Rights Agent (the “Rights Agent”).

WHEREAS, under Section 27 of the Rights Agreement, the Company may from time to time supplement or amend the Rights Agreement without the approval of any holders of the Rights in order to, among other thing, make any provisions with respect to the Rights that the Company may deem necessary or desirable, any such supplement or amendment to be evidenced by a writing signed by the Company and the Rights Agent;

WHEREAS, the Company has determined, and has so directed the Rights Agent, to amend the Rights Agreement as set forth herein pursuant to Section 27 of the Rights Agreement.

NOW, THEREFORE, in consideration of the foregoing and the mutual agreements set forth herein, and intending to be legally bound, the parties hereto agree as follows:

1. The first sentence of Section 1(a) is restated to read in its entirety as follows:

““Acquiring Person” shall mean any Person who or which, together with all Affiliates and Associates of such Person, shall be the Beneficial Owner of 15% or more of the shares of Common Stock then outstanding, but shall not include (i) the Company, (ii) any Subsidiary of the Company, (iii) any employee benefit plan of the Company or of any Subsidiary of the Company, or (iv) any Person organized, appointed or established by the Company for or pursuant to the terms of any such plan.”

2. Section 1(m) of the Rights Agreement is hereby deleted in its entirety and replaced with the following language:

“Intentionally omitted.”

3. Exhibit C to the Rights Agreement is hereby amended to delete in its entirety the second parenthetical contained in subclause (a) of clause (i) of the second paragraph thereof.

4. This Amendment shall be deemed to be a contract made under the laws of the State of Delaware and for all purposes shall be governed by and construed in accordance with the laws of the State of Delaware applicable to contracts to be made and performed entirely within the State of Delaware.

5. All acts and things necessary to make this Amendment a valid agreement, enforceable according to its terms, have been done and performed, and the execution and

delivery of this Amendment by the Company and the Rights Agent have been in all respects duly authorized by the Company and the Rights Agent.

6. This Amendment may be executed in any number of counterparts and each of such counterparts shall for all purposes be deemed to be an original, and all such counterparts shall together constitute but one and the same instrument.

7. In all respects not inconsistent with the terms and provisions of this Amendment, the Rights Agreement is hereby ratified, adopted, approved and confirmed. In executing and delivering this Amendment, the Rights Agent shall be entitled to all the privileges and immunities afforded to the Rights Agent under the terms and conditions of the Rights Agreement.

8. Capitalized terms used herein and not otherwise defined shall have the meanings given to such terms in the Rights Agreement.

IN WITNESS WHEREOF, the parties hereto have caused this Amendment to be duly executed and attested, as of the date first set forth above.

Attest:		NMT MEDICAL, INC.
By:	/S/    LISA KUZNIAR	By:	/S/    RICHARD E. DAVIS
	Name: Lisa Kuzniar Title: Accountant		Name: Richard E Davis Title: Vice President and Chief Financial Officer

Attest:		AMERICAN STOCK TRANSFER & TRUST COMPANY
By:	/S/    ANTHONY J. FOTI	By:	/S/    HERBERT J. LEMMER
	Name: Anthony J. Foti Title: Account Executive		Name: Herbert J. Lemmer Title: Corporate Counsel