(Check One): x   Form 10-K ¨   Form 20-F ¨   Form 11-K ¨   Form 10-Q ¨   Form 10-D ¨   Form N-SAR ¨   Form N-CSR	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 12b-25 NOTIFICATION OF LATE FILING	OMB APPROVAL
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		SEC FILE NUMBER 000-21001
		CUSIP NUMBER 629294109

For Period Ended: 12/31/2010

x   Transition Report on Form 10-K

¨   Transition Report on Form 20-F

¨   Transition Report on Form 11-K

¨   Transition Report on Form 10-Q

¨   Transition Report on Form N-SAR

For the Transition Period Ended:                                                              

Nothing in this form shall be construed to imply that the Commission has verified any information contained herein.

If the notification relates to a portion of the filing checked above, identify the Item(s) to which the notification relates:             

PART I - REGISTRANT INFORMATION

NMT Medical, Inc.

Full Name of Registrant

Former Name if Applicable

27 Wormwood Street, Boston, MA 02210-1625

Address of Principal Executive Office

PART II - RULES 12b-25(b) AND (c)

If the subject report could not be filed without unreasonable effort or expense and the registrant seeks relief pursuant to Rule 12b-25(b), the following should be completed. (Check box if appropriate)

x	(a)	The reasons described in reasonable detail in Part III of this form could not be eliminated without unreasonable effort or expense;
	(b)	The subject annual report, semi-annual report, transition report on Form 10-K, Form 20-F, Form 11-K, Form N-SAR or Form N-CSR, or portion thereof, will be filed on or before the fifteenth calendar day following the prescribed due date; or the subject quarterly report or transition report on Form 10-Q or subject distribution report on Form 10-D, or portion thereof, will be filed on or before the fifth calendar day following the prescribed due date; and
	(c)	The accountant’s statement or other exhibit required by Rule 12b-25(c) has been attached if applicable.

PART III - NARRATIVE

State below in reasonable detail why Forms 10-K, 20-F, 11-K, 10-Q, 10-D, N-SAR, N-CSR, or the transition report or portion thereof, could not be filed within the prescribed time period.

As we reported in our quarterly filing on Form 10-Q for the quarter ended September 30, 2010, our existing cash resources were not sufficient to fund our business plans, as currently constituted, beyond the fourth quarter of 2010. In response to this liquidity issue, the Company has streamlined its operations and significantly curtailed expenses while, at the same time, seeking sources of capital through potential debt and equity financings and/or strategic transactions including the potential sale of the Company. The Company to date has not been able to raise additional debt or equity capital and has continued to explore its strategic options. Although the Company's outside auditors commenced its audit with respect to the year ended December 31, 2010, the completion of the audit was postponed by us. The Company does not anticipate its outside auditors to complete the audit for the year ended December 31, 2010 unless deemed prudent by the Company to do so in light of the Company's strategic options. There can be no assurance that a strategic transaction will be consummated or that the Company will be able to engage an auditor of its financial statements for the year ended December 31, 2010.

SEC 1344 (05-06)
Persons who are to respond to the collection of information contained in
this form are not required to respond unless the form displays a currently
valid OMB control number.

(Attach Extra Sheets if Needed)

PART IV - OTHER INFORMATION

(1) Name and telephone number of person to contact in regard to this notification

Richard E. Davis	617-737-0930
(Name)	(Telephone Number)

(2) Have all other periodic reports required under Section 13 or 15(d) of the Securities Exchange Act of 1934 or Section 30 of the Investment Company Act of 1940 during the preceding 12 months or for such shorter period that the registrant was required to file such report(s) been filed? If answer is no, identify report(s).     x   Yes     ¨   No

(3) Is it anticipated that any significant change in results of operations from the corresponding period for the last fiscal year will be reflected by the earnings statements to be included in the subject report or portion thereof?     ¨   Yes     x   No

If so, attach an explanation of the anticipated change, both narratively and quantitatively, and, if appropriate, state the reasons why a reasonable estimate of the results cannot be made.

NMT Medical, Inc.

(Name of Registrant as Specified in Charter)

has caused this notification to be signed on its behalf by the undersigned hereunto duly authorized.

Date	04/01/2011	By	/s/ Richard E. Davis
			Richard E. Davis President and Chief Executive Officer