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**Exhibit  12.1**

**CERTIFICATION**

|      I,      Julio M. De Vido, certify that:                                                                                                                                                                                                                                                                                                                                                                                                       |
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|      1.           I have reviewed this annual report on Form 20-F of YPF Sociedad Anónima      (the “Company”);                                                                                                                                                                                                                                                                                          |
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|      2.           Based on my knowledge, this report does not contain any untrue statement      of a material fact oromit      to state a material fact necessary to make the statements made, in light      of the circumstances under which suchstatements      were made, not misleading with respect to the period covered by this report;                                                                            |
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|      3.           Based on my knowledge, the financial statements, and other financial information      included in thisreport,      fairly present in all material respects the financial condition, results      of operations and cash flows of theCompany      as of, and for, the periods presented in this report;                                                                                                  |
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|      4.           The company’s other certifying officers and I are responsible for establishing      and maintainingdisclosure      controls and procedures (as defined in Exchange Act Rules 13a-15(e) and      15d-15(e)) and internal controlover      financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f))      for the Company and have:                                             |
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|      (a)           Designed such disclosure controls and procedures, or caused such disclosure      controls andprocedures      to be designed under our supervision, to ensure that material information      relating to the Company,including      its consolidated subsidiaries, is made known to us by others within those      entities, particularly during theperiod      in which this report is being prepared; |
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|      (b)           Designed such internal control over financial reporting, or caused such      internal control overfinancial      reporting to be designed under our supervision, to provide reasonable assurance      regarding the reliability offinancial      reporting and the preparation of financial statements for external purposes      in accordance with generallyaccepted      accounting principles;     |
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|      (c)           Evaluated the effectiveness of the Company’s disclosure controls and      procedures and presented inthis      report our conclusions about the effectiveness of the disclosure controls      and procedures, as of the end of theperiod      covered by this report based on such evaluation; and                                                                                                |
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|      (d)           Disclosed in this report any change in the Company’s internal control      over financial reporting thatoccurred      during the period covered by the annual report that has materially affected,      or is reasonably likely tomaterially      affect, the Company’s internal control over financial reporting; and                                                                       |
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|      5.           The company’s other certifying officers and I have disclosed, based      on our most recent evaluationof      internal control over financial reporting, to the Company’s auditors      and the audit committee of the Company’sboard      of directors (or persons performing the equivalent functions):                                                                                |
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|      (a)           All significant deficiencies and material weaknesses in the design or operation      of internal controlover      financial reporting which are reasonably likely to adversely affect the      Company’s ability to record, process,summarize      and report financial information; and                                                                                                          |
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|      (b)           Any fraud, whether or not material, that involves management or other employees      who have asignificant      role in the Company’s internal control over financial reporting.                                                                                                                                                                                                                  |
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| Date:May      15, 2012 |   |                     |                             |
|------------------------|--------|--------------------------|----------------------------------|
|                   | By:    | /s/JULIO      M. DE VIDO |
|                   |   |                          |
|                   |   | Name:                    | JULIO      M. DE VIDO            |
|                   |   | Title:                   | Intervenor                       |
|                   |   |                     | Principal      Executive Officer |
|                   |   |                     | Principal      Financial Officer |

 

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