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| x | Annual report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 |
|---|-------------------------------------------------------------------------------------------|

|  ̈ | Transition report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 |
|--------|-----------------------------------------------------------------------------------------------|

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|                                                          |         |                                   |
|---------------------------------------------------------------|--------------|----------------------------------------|
| Washington                                                    |    | 91-1405022                             |
| (State or other jurisdictionof incorporation or organization) |    | (I.R.S. EmployerIdentification Number) |

| Title of Each Class           |    | Name of Each Exchange on Which Registered |
|-------------------------------|--------------|-------------------------------------------|
| Common Stock, $0.01 par value |    | Nasdaq Global Select Market               |

|                                                                                                                             |         |                                         |
|----------------------------------------------------------------------------------------------------------------------------------|--------------|----------------------------------------------|
|        Large accelerated filer    ̈                                             |    | Accelerated filer   x              |
|        Non-accelerated filer    ̈ (Do not check if a smaller reporting company) |    | Smaller reporting company    ̈ |

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| •   | 31.3 Certification of Principal Executive Officer pursuant to Section 302 of the Sarbanes-Oxley Act of 2002; |
|---------------------|--------------------------------------------------------------------------------------------------------------|

| •   | 31.4 Certification of Principal Financial Officer pursuant to Section 302 of the Sarbanes-Oxley Act of 2002; |
|---------------------|--------------------------------------------------------------------------------------------------------------|

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

| ExhibitNo.         |   | Description                                                                                                                                                                             |
|--------------------|--------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
|   1.1(K) |   | Underwriting Agreement between J.P. Morgan Securities Inc. and the registrant dated July 10, 2007 (exhibit 1.1)                                                               |
|               |   |
|   2.1(R) |   | Share Purchase Agreement dated May 26, 2010 by and among SonoSite, Inc., VisualSonics, Inc., the Shareholders of VisualSonics, Inc. and the Shareholders’ Agent (exhibit 2.1)     |
|               |   |
|   3.1(W) |   | Amended and Restated Articles of Incorporation of the registrant (exhibit 10.1)                                                                                                    |
|               |   |
|   3.2(A) |   | Amended and Restated Bylaws of the registrant (exhibit 3.1)                                                                                                                        |
|               |   |
|   4.1(K) |   | First Supplemental Indenture between Wells Fargo Bank, NA and the registrant dated July 16, 2007 (exhibit 4.1)                                                                |
|               |   |
|   4.2(M) |   | Amended and Restated Rights Agreement dated November 28, 2007 by and between the registrant and Computershare Trust Company N.A. (exhibit 4.1)                                |
|               |   |
|   4.3(M) |   | Form of Rights Certificate (exhibit 4.2)                                                                                                                                           |
|               |   |
| 10.1(F)            |   | 1998 Stock Option Plan, as amended and restated (exhibit 10.1)                                                                                                                     |
|               |   |
| 10.2(U)            |   | Terms of Stock Option Grant Program for Nonemployee Directors under the SonoSite, Inc. 1998 Stock Option Plan (exhibit 10.2)                                                       |
|               |   |
| 10.3(G)            |   | 1998 Nonofficer Employee Stock Option Plan, as amended and restated (exhibit 10.1)                                                                                                 |
|               |   |
| 10.4(D)            |   | Nonemployee Director Stock Option Plan, as amended and restated (exhibit 10.3)                                                                                                     |
|               |   |
| 10.5(B)            |   | Management Incentive Compensation Plan (exhibit 10.5)                                                                                                                              |
|               |   |
| 10.6(U)            |   | Technology Transfer and License Agreement between ATL Ultrasound, Inc. and the registrant, effective as of April 6, 1998, as amended (exhibit 10.9)                           |
|               |   |
| 10.7(E)            |   | Third Amendment to Technology Transfer and License Agreement between ATL Ultrasound, Inc. and the registrant, dated as of March 10, 2000 (exhibit 10.9)                            |
|               |   |
| 10.8(C)            |   | Option Notice Agreement, dated July 17, 2000, between the registrant and Michael J. Schuh (exhibit 99.1)                                                                      |
|               |   |
| 10.9(H)            |   | 2005 Employee Stock Purchase Plan (exhibit 10.2)                                                                                                                                   |
|               |   |
| 10.10(I)           |   | 1998 Stock Option Plan Stock Option Award Agreement (exhibit 10.1)                                                                                                                 |
|               |   |
| 10.11(J)           |   | Terms of Stock Option Grant Program for Nonemployee Directors under the SonoSite, Inc. 2005 Stock Incentive Plan (exhibit 10.1)                                                    |
|               |   |
| 10.12(J)           |   | 2005 Stock Incentive Plan Stock Option Agreement (Non Statutory) (exhibit 10.2)                                                                                                    |
|               |   |
| 10.13(J)           |   | 2005 Stock Incentive Plan Restricted Stock Unit Agreement (exhibit 10.3)                                                                                                           |
|               |   |
| 10.14(L)           |   | Call Option Transaction Confirmation, dated as of July 11, 2007, by and between SonoSite, Inc. and JPMorgan Chase Bank, National Association (exhibit 10.1)                        |
|               |   |
| 10.15(L)           |   | Warrant Transaction Confirmation, dated as of July 11, 2007, by and between SonoSite, Inc. and JPMorgan Chase Bank, National Association (exhibit 10.2)                       |
|               |   |
| 10.16(V)           |   | Form of Partial Unwind Agreement with respect to the Note Hedge Transaction Confirmation dated July 11, 2007, by and between SonoSite, Inc. and JP Morgan Chase Bank, NA (exhibit 10.1) |
|               |   |
| 10.17(V)           |   | Form of Partial Unwind Agreement with respect to the Warrant Confirmation dated July 11, 2007, by and between SonoSite, Inc. and JPMorgan Chase Bank, NA (exhibit 10.2)                 |
|               |   |
| 10.18(N)           |   | Amended and Restated 2005 Stock Incentive Plan (exhibit 99.1)                                                                                                                           |

|        |   |                                                                                                                                            |
|-------------|--------|-------------------------------------------------------------------------------------------------------------------------------------------------|
| 10.19(O)    |   | FY2010 Variable Incentive Bonus Plan (exhibit 10.1)                                                                                             |
|        |   |
| 10.20(P)    |   | Form of Senior Management Employment Agreement by and between SonoSite, Inc. and each of its Named Executive Officers (exhibit 10.20)           |
|        |   |
| 10.21(Q)    |   | Form of Indemnification Agreement by and between SonoSite, Inc. and each of its Named Executive Officers (exhibit 10.21)                        |
|        |   |
| 10.22(S)*   |   | Confidential Settlement and License Agreement dated October 16, 2009 by and between SonoSite, Inc. and General Electric Company (exhibit 10.22) |
|        |   |
| 10.23(T)    |   | Separation Agreement and General Release dated January 14, 2011 by and between SonoSite, Inc. and Michael Schuh (exhibit 10.1)                  |
|        |   |
| 21.1**      |   | Subsidiaries of the registrant                                                                                                                  |
|        |   |
| 23.1**      |   | Consent of KPMG LLP, independent registered public accounting firm                                                                              |
|        |   |
| 24.1**      |   | Power of attorney (contained on signature page)                                                                                                 |
|        |   |
| 31.1**      |   | Certification of Principal Executive Officer pursuant to Section 302 of the Sarbanes-Oxley Act of 2002                                     |
|        |   |
| 31.2**      |   | Certification of Principal Financial Officer pursuant to Section 302 of the Sarbanes-Oxley Act of 2002                                     |
|        |   |
| 31.3† |   | Certification of Principal Executive Officer pursuant to Section 302 of the Sarbanes-Oxley Act of 2002                                     |
|        |   |
| 31.4† |   | Certification of Principal Financial Officer pursuant to Section 302 of the Sarbanes-Oxley Act of 2002                                     |
|        |   |
| 32.1**      |   | Certification of Principal Executive Officer pursuant to 18 U.S.C. Section 1350 (Section 906 of the Sarbanes-Oxley Act of 2002)  |
|        |   |
| 32.2**      |   | Certification of Principal Financial Officer pursuant to 18 U.S.C. Section 1350 (Section 906 of the Sarbanes-Oxley Act of 2002)  |

| † | Filed herewith.                                                                                                                                                                             |
|---------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| *       | Confidential treatment requested.                                                                                                                                                           |
| **      | Previously filed.                                                                                                                                                                           |
| (A)     | Incorporated by reference to the designated exhibit included in SonoSite’s report on Form 10-Q filed on November 9, 2010.                                                        |
| (B)     | Incorporated by reference to the designated exhibit included in SonoSite’s report on Form 10-K for the year ended December 31, 1998 filed on March 22, 1999.           |
| (C)     | Incorporated by reference to the designated exhibit included in SonoSite’s registration statement on Form S-8 (Registration No. 333-51820) filed on December 14, 2000. |
| (D)     | Incorporated by reference to the designated exhibit included in SonoSite’s report on Form 8-K filed on February 7, 2006.                                                         |
| (E)     | Incorporated by reference to the designated exhibit included in SonoSite’s report on Form 10-K for the year ended December 31, 2001 filed on February 22, 2002.        |
| (F)     | Incorporated by reference to the designated exhibit included in SonoSite’s report on Form 10-Q for the quarter ended March 31, 2002 filed on May 13, 2002.             |
| (G)     | Incorporated by reference to the designated exhibit included in SonoSite’s report on Form 10-Q for the quarter ended June 30, 2002 filed on August 13, 2002.           |
| (H)     | Incorporated by reference to the designated exhibit included in SonoSite’s report on Form 8-K filed on April 28, 2005.                                                      |
| (I)     | Incorporated by reference to the designated exhibit included in SonoSite’s report on Form 10-Q for the quarter ended June 30, 2005 filed on August 9, 2005.            |
| (J)     | Incorporated by reference to the designated exhibit included in SonoSite’s report on Form 8-K filed on February 7, 2006.                                                    |
| (K)     | Incorporated by reference to the designated exhibit included in SonoSite’s report on Form 8-K filed on July 16, 2007.                                                       |
| (L)     | Incorporated by reference to the designated exhibit included in SonoSite’s report on Form 10-Q filed on August 9, 2007.                                                     |

| (M) | Incorporated by reference to the designated exhibit included in SonoSite’s report on Form 8-K filed on November 29, 2007.                                     |
|-----|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| (N) | Incorporated by reference to the designated exhibit included in SonoSite’s registration statement on Form S-8 filed on May 2, 2008.                           |
| (O) | Incorporated by reference to the designated exhibit included in SonoSite’s report on Form 10-Q for the quarter ended March 31, 2010 and filed on May 7, 2010. |
| (P) | Incorporated by reference to the designated exhibit included in SonoSite’s report on Form 10-K filed on March 12, 2009.                                            |
| (Q) | Incorporated by reference to the designated exhibit included in SonoSite’s report on Form 10-K filed on March 26, 2010.                                                 |
| (R) | Incorporated by reference to the designated exhibit included in SonoSite’s report on Form 8-K/A filed on December 7, 2010.                                              |
| (S) | Incorporated by reference to the designated exhibit included in SonoSite’s report on Form 10-K/A filed on September 7, 2010.                                            |
| (T) | Incorporated by reference to the designated exhibit included in SonoSite’s report on Form 8-K filed on January 18, 2011.                                                |
| (U) | Incorporated by reference to the designated exhibit included in SonoSite’s Registration Statement on Form S-1 (Registration No. 333-714157) filed on March 10, 1999.    |
| (V) | Incorporated by reference to the designated exhibit included in SonoSite’s report on Form 8-K filed on November 2, 2008.                                                |
| (W) |  Incorporated by reference to the designated exhibit included in SonoSite's report on Form 8-K filed on April 23, 2010.                                                  |

|   |                   |                                                             |
|--------|------------------------|------------------------------------------------------------------|
|   |                   |  SONOSITE, INC.                                             |
|   |                   |
|   |   By    |  /s/ Marcus Y. Smith                                        |
|   |                   | Marcus Y. SmithSenior Vice President and Chief Financial Officer |

| ExhibitNo.         |   | Description                                                                                                                                                                             |
|--------------------|--------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
|   1.1(K) |   | Underwriting Agreement between J.P. Morgan Securities Inc. and the registrant dated July 10, 2007 (exhibit 1.1)                                                               |
|               |   |
|   2.1(R) |   | Share Purchase Agreement dated May 26, 2010 by and among SonoSite, Inc., VisualSonics, Inc., the Shareholders of VisualSonics, Inc. and the Shareholders’ Agent (exhibit 2.1)     |
|               |   |
|   3.1(W) |   | Amended and Restated Articles of Incorporation of the registrant (exhibit 10.1)                                                                                                    |
|               |   |
|   3.2(A) |   | Amended and Restated Bylaws of the registrant (exhibit 3.1)                                                                                                                        |
|               |   |
|   4.1(K) |   | First Supplemental Indenture between Wells Fargo Bank, NA and the registrant dated July 16, 2007 (exhibit 4.1)                                                                |
|               |   |
|   4.2(M) |   | Amended and Restated Rights Agreement dated November 28, 2007 by and between the registrant and Computershare Trust Company N.A. (exhibit 4.1)                                |
|               |   |
|   4.3(M) |   | Form of Rights Certificate (exhibit 4.2)                                                                                                                                           |
|               |   |
| 10.1(F)            |   | 1998 Stock Option Plan, as amended and restated (exhibit 10.1)                                                                                                                     |
|               |   |
| 10.2(U)            |   | Terms of Stock Option Grant Program for Nonemployee Directors under the SonoSite, Inc. 1998 Stock Option Plan (exhibit 10.2)                                                       |
|               |   |
| 10.3(G)            |   | 1998 Nonofficer Employee Stock Option Plan, as amended and restated (exhibit 10.1)                                                                                                 |
|               |   |
| 10.4(D)            |   | Nonemployee Director Stock Option Plan, as amended and restated (exhibit 10.3)                                                                                                     |
|               |   |
| 10.5(B)            |   | Management Incentive Compensation Plan (exhibit 10.5)                                                                                                                              |
|               |   |
| 10.6(U)            |   | Technology Transfer and License Agreement between ATL Ultrasound, Inc. and the registrant, effective as of April 6, 1998, as amended (exhibit 10.9)                           |
|               |   |
| 10.7(E)            |   | Third Amendment to Technology Transfer and License Agreement between ATL Ultrasound, Inc. and the registrant, dated as of March 10, 2000 (exhibit 10.9)                            |
|               |   |
| 10.8(C)            |   | Option Notice Agreement, dated July 17, 2000, between the registrant and Michael J. Schuh (exhibit 99.1)                                                                      |
|               |   |
| 10.9(H)            |   | 2005 Employee Stock Purchase Plan (exhibit 10.2)                                                                                                                                   |
|               |   |
| 10.10(I)           |   | 1998 Stock Option Plan Stock Option Award Agreement (exhibit 10.1)                                                                                                                 |
|               |   |
| 10.11(J)           |   | Terms of Stock Option Grant Program for Nonemployee Directors under the SonoSite, Inc. 2005 Stock Incentive Plan (exhibit 10.1)                                                    |
|               |   |
| 10.12(J)           |   | 2005 Stock Incentive Plan Stock Option Agreement (Non Statutory) (exhibit 10.2)                                                                                                    |
|               |   |
| 10.13(J)           |   | 2005 Stock Incentive Plan Restricted Stock Unit Agreement (exhibit 10.3)                                                                                                           |
|               |   |
| 10.14(L)           |   | Call Option Transaction Confirmation, dated as of July 11, 2007, by and between SonoSite, Inc. and JPMorgan Chase Bank, National Association (exhibit 10.1)                        |
|               |   |
| 10.15(L)           |   | Warrant Transaction Confirmation, dated as of July 11, 2007, by and between SonoSite, Inc. and JPMorgan Chase Bank, National Association (exhibit 10.2)                       |
|               |   |
| 10.16(V)           |   | Form of Partial Unwind Agreement with respect to the Note Hedge Transaction Confirmation dated July 11, 2007, by and between SonoSite, Inc. and JP Morgan Chase Bank, NA (exhibit 10.1) |
|               |   |
| 10.17(V)           |   | Form of Partial Unwind Agreement with respect to the Warrant Confirmation dated July 11, 2007, by and between SonoSite, Inc. and JPMorgan Chase Bank, NA (exhibit 10.2)                 |
|               |   |
| 10.18(N)           |   | Amended and Restated 2005 Stock Incentive Plan (exhibit 99.1)                                                                                                                           |

|        |   |                                                                                                                                            |
|-------------|--------|-------------------------------------------------------------------------------------------------------------------------------------------------|
| 10.19(O)    |   | FY2010 Variable Incentive Bonus Plan (exhibit 10.1)                                                                                             |
|        |   |
| 10.20(P)    |   | Form of Senior Management Employment Agreement by and between SonoSite, Inc. and each of its Named Executive Officers (exhibit 10.20)           |
|        |   |
| 10.21(Q)    |   | Form of Indemnification Agreement by and between SonoSite, Inc. and each of its Named Executive Officers (exhibit 10.21)                        |
|        |   |
| 10.22(S)*   |   | Confidential Settlement and License Agreement dated October 16, 2009 by and between SonoSite, Inc. and General Electric Company (exhibit 10.22) |
|        |   |
| 10.23(T)    |   | Separation Agreement and General Release dated January 14, 2011 by and between SonoSite, Inc. and Michael Schuh (exhibit 10.1)                  |
|        |   |
| 21.1**      |   | Subsidiaries of the registrant                                                                                                                  |
|        |   |
| 23.1**      |   | Consent of KPMG LLP, independent registered public accounting firm                                                                              |
|        |   |
| 24.1**      |   | Power of attorney (contained on signature page)                                                                                                 |
|        |   |
| 31.1**      |   | Certification of Principal Executive Officer pursuant to Section 302 of the Sarbanes-Oxley Act of 2002                                     |
|        |   |
| 31.2**      |   | Certification of Principal Financial Officer pursuant to Section 302 of the Sarbanes-Oxley Act of 2002                                     |
|        |   |
| 31.3† |   | Certification of Principal Executive Officer pursuant to Section 302 of the Sarbanes-Oxley Act of 2002                                     |
|        |   |
| 31.4† |   | Certification of Principal Financial Officer pursuant to Section 302 of the Sarbanes-Oxley Act of 2002                                     |
|        |   |
| 32.1**      |   | Certification of Principal Executive Officer pursuant to 18 U.S.C. Section 1350 (Section 906 of the Sarbanes-Oxley Act of 2002)  |
|        |   |
| 32.2**      |   | Certification of Principal Financial Officer pursuant to 18 U.S.C. Section 1350 (Section 906 of the Sarbanes-Oxley Act of 2002)  |

| † | Filed herewith.                                                                                                                                                                             |
|---------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| *       | Confidential treatment requested.                                                                                                                                                           |
| **      | Previously filed.                                                                                                                                                                           |
| (A)     | Incorporated by reference to the designated exhibit included in SonoSite’s report on Form 10-Q filed on November 9, 2010.                                                        |
| (B)     | Incorporated by reference to the designated exhibit included in SonoSite’s report on Form 10-K for the year ended December 31, 1998 filed on March 22, 1999.           |
| (C)     | Incorporated by reference to the designated exhibit included in SonoSite’s registration statement on Form S-8 (Registration No. 333-51820) filed on December 14, 2000. |
| (D)     | Incorporated by reference to the designated exhibit included in SonoSite’s report on Form 8-K filed on February 7, 2006.                                                         |
| (E)     | Incorporated by reference to the designated exhibit included in SonoSite’s report on Form 10-K for the year ended December 31, 2001 filed on February 22, 2002.        |
| (F)     | Incorporated by reference to the designated exhibit included in SonoSite’s report on Form 10-Q for the quarter ended March 31, 2002 filed on May 13, 2002.             |
| (G)     | Incorporated by reference to the designated exhibit included in SonoSite’s report on Form 10-Q for the quarter ended June 30, 2002 filed on August 13, 2002.           |
| (H)     | Incorporated by reference to the designated exhibit included in SonoSite’s report on Form 8-K filed on April 28, 2005.                                                      |
| (I)     | Incorporated by reference to the designated exhibit included in SonoSite’s report on Form 10-Q for the quarter ended June 30, 2005 filed on August 9, 2005.            |
| (J)     | Incorporated by reference to the designated exhibit included in SonoSite’s report on Form 8-K filed on February 7, 2006.                                                    |
| (K)     | Incorporated by reference to the designated exhibit included in SonoSite’s report on Form 8-K filed on July 16, 2007.                                                       |
| (L)     | Incorporated by reference to the designated exhibit included in SonoSite’s report on Form 10-Q filed on August 9, 2007.                                                     |

| (M) | Incorporated by reference to the designated exhibit included in SonoSite’s report on Form 8-K filed on November 29, 2007.                                     |
|-----|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| (N) | Incorporated by reference to the designated exhibit included in SonoSite’s registration statement on Form S-8 filed on May 2, 2008.                           |
| (O) | Incorporated by reference to the designated exhibit included in SonoSite’s report on Form 10-Q for the quarter ended March 31, 2010 and filed on May 7, 2010. |
| (P) | Incorporated by reference to the designated exhibit included in SonoSite’s report on Form 10-K filed on March 12, 2009.                                            |
| (Q) | Incorporated by reference to the designated exhibit included in SonoSite’s report on Form 10-K filed on March 26, 2010.                                                 |
| (R) | Incorporated by reference to the designated exhibit included in SonoSite’s report on Form 8-K/A filed on December 7, 2010.                                              |
| (S) | Incorporated by reference to the designated exhibit included in SonoSite’s report on Form 10-K/A filed on September 7, 2010.                                            |
| (T) | Incorporated by reference to the designated exhibit included in SonoSite’s report on Form 8-K filed on January 18, 2011.                                                |
| (U) | Incorporated by reference to the designated exhibit included in SonoSite’s Registration Statement on Form S-1 (Registration No. 333-714157) filed on March 10, 1999.    |
| (V) | Incorporated by reference to the designated exhibit included in SonoSite’s report on Form 8-K filed on November 2, 2008.                                                |
| (W) |  Incorporated by reference to the designated exhibit included in SonoSite's report on Form 8-K filed on April 23, 2010.                                                  |