Aneurysmal bone cyst (ABC) is an unusual expansile lesion of bone which may arise within the mandible on rare occasions. This lesion may arise with very few signs or symptoms. Surgical treatment consists of complete excision or curettage. The recurrence rate may be high in lesions which are incompletely excised. Three cases of aneurysmal bone cysts in children will be presented, demonstrating the wide variation of clinical presentation. One case required an extensive mandibular resection, necessitating the first reported microvascular mandible reconstruction for this entity in a pediatric patient. © 1995.