FORM 6-K

                      SECURITIES AND EXCHANGE COMMISSION
                            WASHINGTON, D.C. 20549

                       Report of Foreign Private Issuer

                       Pursuant to Rule 13a-16 or 15d-16
                       of the Securities Exchange Act of
                                     1934


                                October 23, 2007

                       Commission File Number 001-14978


                              SMITH & NEPHEW plc
                              (Registrant's name)


                                15 Adam Street
                           London, England WC2N 6LA
             (Address of registrant's principal executive offices)


     [Indicate by check mark whether the registrant files or will file annual
reports under cover Form 20-F or Form 40-F.]

               Form 20-F  X                   Form 40-F
                         ---                            ---

     [Indicate by check mark if the registrant is submitting the Form 6-K in
paper as permitted by Regulation S-T Rule 101(b)(1).]

               Yes                            No  X
                   ---                           ---

     [Indicate by check mark if the registrant is submitting the Form 6-K in
paper as permitted by Regulation S-T Rule 101(b)(7).]

               Yes                            No  X
                   ---                           ---

     [Indicate by check mark whether by furnishing the information contained
in this Form, the registrant is also thereby furnishing information to the
Commission pursuant to Rule 12g3-2 (b) under the Securities Exchange Act of
1934.]

               Yes                            No  X
                   ---                           ---

     If "Yes" is marked, indicate below the file number assigned to the
registrant in connection with Rule 12g3-2 (b) : 82- n/a.





                                  SIGNATURES

     Pursuant to the requirements of the Securities Exchange Act of 1934, the
registrant has duly caused this report to be signed on its behalf by the
undersigned thereunto duly authorized.


                                                 Smith & Nephew plc
                                                 (Registrant)


Date: October 23, 2007
                                                  By:   /s/ Paul Chambers
                                                        -----------------
                                                 Paul Chambers
                                                 Company Secretary



23 October  2007


Transaction in own shares.


Smith & Nephew plc announces that on 23 October 2007 it purchased 230,000
ordinary shares of US$0.20 each at a price of 624.5082 pence per share. The
purchased shares will be held as treasury shares.

Following the above purchase, Smith & Nephew plc holds 42,520,000 ordinary
shares in treasury, and has 904,063,964 ordinary shares in issue (excluding
treasury shares).


Paul Chambers
Company Secretary