Exhibit
12.1

Certification
Pursuant to Rule 13a-14(a) or Rule 15d-14(a)
of the Securities Exchange Act of 1934

|                                        |    |                                                                                                                                                                                                                                                                                                                                                                                          
|--------------------------------------- | -- | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|I, Rodrigo Guzmán Perera, certify that:
|                                        |    |                                                                                                                                                                                                                                                                                                                                                                                          
|                                        | 1. | have reviewed this annual report on Form 20-F of
  Grupo Aeroportuario del Pacífico, S.A.B. de C.V.;                                                                                                                                                                                                                                                                                     
|                                        |    |                                                                                                                                                                                                                                                                                                                                                                                          
|                                        | 2. | Based on my knowledge, this report does not contain
  any untrue statement of a material fact or omit to state a material fact
  necessary to make the statements made, in light of the circumstances under
  which such statements were made, not misleading with respect to the period
  covered by this report;                                                                       
|                                        |    |                                                                                                                                                                                                                                                                                                                                                                                          
|                                        | 3. | Based on my knowledge, the financial statements, and
  other financial information included in this report, fairly present in all
  material respects the financial condition, results of operations and cash
  flows of the company as of, and for, the periods presented in this report;                                                                                               
|                                        |    |                                                                                                                                                                                                                                                                                                                                                                                          
|                                        | 4. | The companys other certifying officer(s) and I are
  responsible for establishing and maintaining disclosure controls and
  procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) for the
  company and have:                                                                                                                                                           
|                                        |    |                                                                                                                                                                                                                                                                                                                                                                                          
|                                        |    | (a) Designed such disclosure controls and
  procedures, or caused such disclosure controls and procedures 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 the period in which this
  report is being prepared;
|                                        |    |                                                                                                                                                                                                                                                                                                                                                                                          
|                                        |    | (b) Evaluated the effectiveness of the companys
  disclosure controls and procedures and presented in this report our
  conclusions about the effectiveness of the disclosure controls and
  procedures, as of the end of the period covered by this report based on such
  evaluation; and                                                                                             
|                                        |    |                                                                                                                                                                                                                                                                                                                                                                                          
|                                        |    | (c) Disclosed in this report any change in the
  companys internal control over financial reporting that occurred during the
  period covered by the annual report that has materially affected, or is
  reasonably likely to materially affect, the companys internal control over
  financial reporting; and                                                                         
|                                        |    |                                                                                                                                                                                                                                                                                                                                                                                          
|                                        | 5. | The companys other certifying officer(s) and I have
  disclosed, based on our most recent evaluation of internal control over
  financial reporting, to the companys auditors and the audit committee of the
  companys board of directors (or persons performing the equivalent
  functions):                                                                                        
|                                        |    |                                                                                                                                                                                                                                                                                                                                                                                          
|                                        |    | (a) All significant deficiencies and material weaknesses in the design or
  operation of internal control over 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 a significant role in the
  companys internal control over financial reporting.

| |                          
| | -------------------------
| | /s/ Rodrigo Guzmán Perera
| |                          
| | Rodrigo Guzmán Perera    
| | Chief Financial Officer  
| |                          
| | Date: June 29, 2007      

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