UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549



FORM 10-K/A

(Amendment No. 1)

|                                                                  |                                                                                         
|----------------------------------------------------------------- | ----------------------------------------------------------------------------------------
|x                                                                 | ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934    
|                                                                  |                                                                                         
|For the fiscal year ended September 30, 2010                     
|                                                                  |                                                                                         
|o                                                                 | TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
|For
            the transition period from                     to
|                                                                 
|Commission file number: 000-21377                                
|                                                                 
|ROFIN-SINAR TECHNOLOGIES INC.                                    
|(Exact name of Registrant as specified in its charter)           



|                                         |  |                    
|---------------------------------------- |  | -------------------
|Delaware                                 |  | 38-3306461         
|(State or other jurisdiction of          |  | (I.R.S. Employer   
|incorporation or organization)           |  | Identification No.)
|                                         |  |                    
|40984 Concept Drive, Plymouth, MI        |  | 48170              
|(Address of principal executive offices) |  | (Zip Code)         
|                                         |  |                    

Registrants
telephone number, including area code: (734) 455-5400



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

|Title of each class                            |  | Name of each exchange on which registered
|---------------------------------------------- |  | -----------------------------------------
|                                               |  |                                          
|Common stock, par value $0.01 per Share        |  | The NASDAQ Global Select Market          
|Rights Associated with common stock, par value |  |                                          
|$0.01 per Share                                |  |                                          

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. YesoNox



Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the



Act. YesoNox



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. YesxNoo





Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Website, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files). YesoNoo



Indicate
    by check mark if disclosure of delinquent filers pursuant to Item 405 of
    Regulation S-K (§229.405 of this chapter) 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.o



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

|                                     |  |                                |  |                                    |  |                                       
|------------------------------------ |  | ------------------------------ |  | ---------------------------------- |  | --------------------------------------
|Large
            accelerated filero |  | Accelerated
            filerx |  | Non-accelerated
            filero |  | Smaller
            reporting companyo

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



The
    aggregate market value of the voting and non-voting common equity held by
    non-affiliates of the registrant based upon the closing price of the common
    stock on March 30, 2010 (the last business day of the most recently completed
    second fiscal quarter) as reported by the NASDAQ Global Select Market was
    approximately $653,218,528. For the purposes hereof, affiliates include
all executive officers and directors of the registrant.



28,397,796
    shares of the registrants common stock, par value $0.01 per share,
were outstanding as of November 29, 2010.



Certain
    sections of the Companys Proxy Statement to be filed in connection with the Companys
    2011 Annual Meeting of Stockholders to be held in March 2011 are incorporated
by reference herein at Part III, Items 10-14.









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EXPLANATORY NOTE

This
    Amendment No. 1 to Form 10-K (this Amendment) amends the Annual Report on Form 10-K for the fiscal year ended September 30, 2010, originally filed on November 30, 2010 (the Original 10-K), of Rofin-Sinar Technologies Inc.., a Delaware corporation (the Company or we). We are filing this Amendment solely to correct an inadvertent clerical error on the cover page of the Original 10-K in which the box identifying the Company as a non-accelerated filer was incorrectly checked.  The clerical error has been corrected in this Amendment by checking the Accelerated filer box
    on the cover page. This Amendment does not reflect events occurring after
    November 30, 2010 or otherwise modify or update the disclosures set forth
    in the Original 10-K, including the financial statements and notes thereto
included in the Original 10-K.







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PART IV



|         |                                           
|-------- | ------------------------------------------
|ITEM 15. | EXHIBITS AND FINANCIAL STATEMENT SCHEDULES



|   |                                                           |                                                                                                                          |  | 
|-- | --------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------ |  | 
|a. | The following documents are filed as part of this report: |                                                                                                                          | 
|   |                                                           |                                                                                                                          |  | 
|   | 3.                                                        | Exhibits                                                                                                                 |  | 
|   |                                                           |                                                                                                                          |  | 
|   |                                                           | The exhibits listed in the accompanying index to exhibits are filed or incorporated by reference as part of this report. |  | 



|               |  |            
|-------------- |  | -----------
|               |  |            
|EXHIBIT
NUMBER |  | DESCRIPTION
|               |  |            
|31.1           |  |            
|               |  |            
|31.2           |  |            
|               |  |            
|32.1           |  |            
|               |  |            
|32.2           |  |            
|               |  |            
|               |  |            







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SIGNATURES



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



|                                       |                                                  |     |                    
|-------------------------------------- | ------------------------------------------------ | --- | -------------------
|Date:          December
      23, 2010 | ROFIN-SINAR TECHNOLOGIES INC.                   
|                                       |                                                  |     |                    
|                                       | By:                                              | /s/ | Günther
      Braun
|                                       |                                                  |     | Günther
      Braun
|                                       | President, Chief Executive Officer, and Director



Pursuant to the requirements of the Securities Act of 1934, this Amendment has been signed below by the following persons on behalf of the registrant and in the capacities and on the dates indicated.



|          |                     |       |                                     |      |                  
|--------- | ------------------- | ----- | ----------------------------------- | ---- | -----------------
|SIGNATURE |                     | TITLE |                                     | DATE
|          |                     |       |                                     |     
|          |                     |       |                                     |      |                  
|/s/       | Peter Wirth         |       | Chairman of the Board               |      | December 23, 2010
|          | Peter Wirth         |       |                                     |      |                  
|          |                     |       |                                     |      |                  
|/s/       | Günther
      Braun |       | President, Chief Executive Officer, |      | December 23, 2010
|          | Günther
      Braun |       |                                     |      |                  
|          |                     |       |                                     |      |                  
|/s/       | Ingrid Mittelstaedt |       | Chief Financial Officer             |      | December 23, 2010
|          | Ingrid Mittelstaedt |       |                                     |      |                  
|          |                     |       |                                     |      |                  
|/s/       | Ralph Reins         |       | Director                            |      | December 23, 2010
|          | Ralph Reins         |       |                                     |      |                  
|          |                     |       |                                     |      |                  
|/s/       | Gary Willis         |       | Director                            |      | December 23, 2010
|          | Gary Willis         |       |                                     |      |                  
|          |                     |       |                                     |      |                  
|/s/       | Carl F. Baasel      |       | Director                            |      | December 23, 2010
|          | Carl F. Baasel      |       |                                     |      |                  
|          |                     |       |                                     |      |                  
|/s/       | Daniel Smoke        |       | Director                            |      | December 23, 2010
|          | Daniel Smoke        |       |                                     |      |                  
|          |                     |       |                                     |      |                  
|/s/       | Stephen Fantone     |       | Director                            |      | December 23, 2010
|          | Stephen Fantone     |       |                                     |      |                  









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INDEX TO EXHIBITS



|            |  |                                                                  
|----------- |  | -----------------------------------------------------------------
|Exhibit No. |  | Exhibit                                                          
|            |  |                                                                  
|31.1        |  | Rule 13a-14(a)/15d-14(a) Certification of Chief Executive Officer
|            |  |                                                                  
|31.2        |  | Rule 13a-14(a)/15d-14(a) Certification of Chief Financial Officer
|            |  |                                                                  
|32.1        |  | Section 1350 Certification of Chief Executive Officer            
|            |  |                                                                  
|32.2        |  | Section 1356 Certification of Chief Financial Officer            











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