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UNITED STATES

   OMB APPROVALSECURITIES AND EXCHANGE COMMISSION

   OMB Number:

   3235-0381Washington, D.C. 20549

   Expires:

   July 31, 2014FORM 40-F/A

   Estimated average burdenhours per response.

   427
 (Amendment No. 1) [ ] REGISTRATION STATEMENT PURSUANT TO SECTION 12 OF THE SECURITIES EXCHANGE ACT OF 1934 OR [X] ANNUAL REPORT PURSUANT TO SECTION 13(a) OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2012    Commission File Number Rio Alto Mining Limited(Exact name of Registrant as specified in its charter) N/A(Translation of Registrant’s name into English (if applicable)) Alberta(Province or other jurisdiction of incorporation or organization) 1040(Primary Standard Industrial Classification Code Number (if applicable)) N/A(I.R.S. Employer Identification Number (if applicable)) Suite 1950 – 400 Burrard Street Vancouver, British Columbia, Canada V6C 3A6 (604) 628-1401 (Address and telephone number of Registrant’s principal executive offices) The Corporation Trust Company1209 Orange StreetWilmington, DE 19801(866) 261-9756(Name, address (including zip code) and telephone number (including area code) of agent for service in the United States)
 Securities registered or to be registered pursuant to Section 12(b) of the Act: Title of Each Class:

   Name of Each Exchange On Which Registered:Common Stock, no par value

   NYSE
 Securities registered or to be registered pursuant to Section 12(g) of the Act: N/A Securities for which there is a reporting obligation pursuant to Section 15(d) of the Act: N/A


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For annual reports, indicate by check mark the information filed with this Form: [ X ] Annual information form    [ X ] Audited annual financial statements Indicate the number of outstanding shares of each of the issuer’s classes of capital or common stock as of the close of the period covered by the annual report: 175,536,962. Indicate by check mark whether the Registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Exchange Act 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. Yes [   ]    No[ X ] Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the Registrant was required to submit and post such files). Yes [   ]    No[   ]


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EXPLANATORY NOTE On March 28, 2013, the Registrant filed its Annual Report on Form 40-F for the year ended December 31, 2012 (the "Annual Report on Form 40-F"), which included as Exhibit 99.3 its Management Discussion and Analysis for the year ended December 31, 2012 (the "MD&A"). The Registrant is filing this Amendment No. 1 to the Annual Report on Form 40-F/A (this "Amendment") to correct information contained in the MD&A under the heading "Operating Outlook for 2013". Included on page 6 of the MD&A is a table outlining estimated 2013 cash production cost, as that term is described in the MD&A, totaling $93.334 million or approximately $465 per ounce. The Company points out that there was a line item missing in such table. The omitted line item was for estimated processing costs of about $15.339 million or approximately $77 per ounce, which would bring the Company's expected cash production cost for 2013 to about $108.673 million or $543 per ounce and would increase total production costs, as described in the MD&A, in the following table on page 6 to $247,284 or $1,236 per ounce an increase from $231,945 and $1,158 per ounce, respectively. The Registrant has included in this Amendment No. 1 new certifications of its Chief Executive Officer and Chief Financial Officer pursuant to Sections 302 and 906 of the Sarbanes-Oxley Act of 2002. Other than as expressly set forth above, this Amendment does not, and does not purport to, update or restate the information in any Item of the Annual Report on Form 40-F or reflect any events that have occurred after the Annual Report on Form 40-F was filed. UNDERTAKING The Company undertakes to make available, in person or by telephone, representatives to respond to inquiries made by the SEC staff, and to furnish promptly, when requested to do so by the SEC staff, information relating to: the securities registered pursuant to Form 40-F; the securities in relation to which the obligation to file an annual report on Form 40-F arises; or transactions in said securities. CONSENT TO SERVICE OF PROCESS The Company filed an Appointment of Agent for Service of Process and Undertaking on Form F-X with the SEC on December 19, 2012, which is hereby incorporated by reference, with respect to the class of securities in relation to which the obligation to file this annual report on Form 40-F arises.


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EXHIBIT INDEX The following exhibits have been filed as part of this annual report: EXHIBIT

   DESCRIPTIONAnnual Information99.1*

   Annual Information Form for the year ended December 31, 201299.2*

   Audited Annual Financial Statements for the year ended December 31, 2012, the seven-month financial year ended December 31, 2011 and the year ended May 31, 201199.3

   Management’s Discussion and Analysis for the year ended December 31, 201299.4*

   Report of Independent Registered Public Accounting FirmCertifications99.5

   Certificate of Chief Executive Officer Pursuant to Rule 13a-14(a) of the Exchange Act99.6

   Certificate of Chief Financial Officer Pursuant to Rule 13a-14(a) of the Exchange Act99.7

   Certificate of Chief Executive Officer Pursuant to 18 U.S. C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 200299.8

   Certificate of Chief Financial Officer Pursuant to 18 U.S. C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002Consents99.9*

   Consent of Grant Thornton LLP99.10*

   Consent of Kirk Mining Consultants Pty Limited99.11*

   Consent of Christopher Edward Kaye, BE (Chem), FAusIMM99.12*

   Consent of Enrique Garay, M Sc P. Geo (MAIG)99.13*

   Consent of Linton Kirk, BE (Mining), FAuslMM99.14*

   Consent of Ian Dreyer, B.App.Sc.(Geology), MAuslMM(CP)
 * Previously filed with the Registrant's Annual Report on Form 40-F, as filed with the Securities and Exchange Commission on March 28, 2013.


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SIGNATURES Pursuant to the requirements of the Exchange Act, the Registrant certifies that it meets all of the requirements for filing on Form 40-F and has duly caused this registration statement to be signed on its behalf by the undersigned, thereto duly authorized. Registrant

   Rio Alto Mining Limited
  By

   /s/“Alexander Black” Alexander BlackPresident and Chief Executive Officer
  Date

   April 2, 2013


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SIGNATURES Pursuant to the requirements of the Exchange Act, the Registrant certifies that it meets all of the requirements for filing on Form 40-F and has duly caused this registration statement to be signed on its behalf by the undersigned, thereto duly authorized. Registrant

   Rio Alto Mining Limited
  By

   /s/“Anthony Hawkshaw”Anthony HawkshawPresident and Chief Executive Officer
  Date

   April 2, 2013


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