The aneurysmal bone cyst is a nonneoplastic, osteolytic and locally destructive lesion that mainly affects the metaphyseal area of long bones and only 2% of it is diagnosed in the maxillofacial skeleton. Although surgical treatment is the most common option, it is associated to high morbidity rates. The case of an aneurysmal bone cyst of a considerable size in a 27-year-old male patient illustrating a conservative surgical approach with preservation of the dental structures in the mandible to limit aesthetic and functional side effects is presented. Two-year clinical follow-up was performed with no evidence of recurrence. Key words: Aneurysmal bone cyst; curettage, conservative treatment, mandibular osteotomy.