Root perforations are accidental events that may occur during the treatment, causing tissue inflammation and alveolar bone loss of integrity of the periodontium. In such cases, the radiological evidence is fundamental in the formulation of the diagnosis, in the choice of therapy (surgical or non-surgical) and finally for the assessment of prognosis of the dental element. In non-surgical treatment of endodontic lesions, the material used for the repair of the defect root should have biocompatibility, antibacterial activity, ability to induce healing of periodontal tissues and radiopacity. The Mineral Trioxide Aggregate (MTA) is a silicate-based cement introduced in dental clinical practice with good radiopacity, biocompatibility and bone induction. This article describes the use of MTA in endodontic repair of a perforation of the middle third root and the success of non-surgical treatment was dimonstrated radiographicaly.