EXHIBIT12.1

CERTIFICATION

I, Claudio Muñoz, certifythat:

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| 1.  | I havereviewed this annual report on Form 20-F of Compañia deTelecomunicaciones de Chile, S.A.; |

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| 2.  | Basedon my knowledge, this report does not contain any untrue statement of amaterial fact or omit to state a material fact necessary to make thestatements made, in light of the circumstances under which suchstatements were made, not misleading with respect to the period coveredby this report; |

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| 3.  | Based on my knowledge,the financial statements, and other financial information included inthis report, fairly present in all material respects the financialcondition, results of operations and cash flows of the company as of,and for, the periods presented in this report; |

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| 4.  | The company's other certifying officersand I are responsible for establishing and maintaining disclosurecontrols and procedures (as defined in Exchange Act Rules 13a-15(e) and15d-15(e)) for the company and have: |

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|  | a)  | Designed such disclosure controlsand procedures or caused such disclosure controls and procedures to bedesigned under our supervision, to ensure that material informationrelating to the company, including its consolidated subsidiaries, ismade known to us by others within those entities, particularly duringthe period in which this report is being prepared; |

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|  | b)  | Evaluated the effectiveness of thecompany's disclosure controls and procedures and presented inthis report our conclusions about the effectiveness of the disclosurecontrols and procedures, as of the end of the period covered by thisreport based on such evaluation; and |

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|  | c)  | Disclosed in this report any changein the company's internal control over financial reporting thatoccurred during the period covered by the annual report that hasmaterially affected, or is reasonably likely to materially affect, thecompany's internal control over financial reporting; and |

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| 5.  | The company's other certifying officersand I have disclosed, based on our most recent evaluation of internalcontrol over financial reporting, to the company's auditors andto the audit committee of the company's board of directors (orpersons performing the equivalent function): |

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|  | a)  | All significant deficiencies andmaterial weaknesses in the design or operation of internal control overfinancial reporting which are reasonably likely to adversely affect thecompany's ability to record, process, summarize and reportfinancial information; and |

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|  | b)  | Anyfraud, whether or not material, that involves management or otheremployees who have a significant role in the company's internalcontrol over financial reporting. |

Date: June 24,2005

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| By:    |  | /s/Claudio Muñoz                                |  |   |
|   |  | Name: ClaudioMuñozTitle: Chief ExecutiveOfficer |  |   |
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