On September 11, 2008, North American Scientific, Inc. entered into a Tenth Amendment to Loan and Security Agreement (the "Amendment") with Silicon Valley Bank which provided for the waiver of the minimum tangible net worth covenant for the periods ended June 30, 2008, July 31, 2008 and August 31, 2008.

The foregoing description of the Amendment does not purport to be complete and is qualified in its entirety by reference to the Amendment, a copy of which is filed hereto as Exhibit 10.1 and incorporated herein by reference.

On September 11, 2008, North American Scientific, Inc. issued a press release announcing its financial results for the third quarter ended July 31, 2008, a copy of which is included in this Form 8-K as Exhibit 99.1 and is incorporated herein by reference.

On September 11, 2008, North American Scientific, Inc. held a conference call with analysts and investors, the transcript of which is furnished as Exhibit 99.2 and is incorporated herein by reference.

The information in this Item 2.02, including Exhibits 99.1 and 99.2, is furnished and shall not be deemed "filed" for the purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liability of that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, except as shall be expressly set forth by specific reference in such a filing.

(d) Exhibits

Exhibit Number                 Description
     10.1      Tenth Amendment to Loan and Security
               Agreement, September 11, 2008, by and
               between Silicon Valley Bank, North American
               Scientific, Inc., a Delaware corporation and
               North American Scientific, Inc., a
               California corporation.
     99.1      Press Release dated September 11, 2008.
     99.2      Transcript of Conference Call held on
               September 11, 2008.