The purpose of this study was to review longitudinally the clinical features, method of treatment, and recurrence rates of 40 cases of aneurysmal bone cyst in children treated at one institution. Twenty-nine patients with histologic confirmation of the diagnosis and minimum follow-up of 2 years were included. Thirteen patients were less than 10 years of age, and 16 were in the second decade of life. The most frequent location of the lesion was the tibia (seven cases). Patients were treated with curettage, curettage and bone grafting, or resection. The overall recurrence rate was 27.5%. Five lesions recurred once, and three recurred twice. The average time before recurrence was 18.7 months. Complications occurred in six cases, three of them with physeal arrest. The lesion occurred more commonly in females in the second decade of life and was not associated with a pre-existing tumor. The recurrence rate dropped after the use of a high-speed bur.