The authors analyzed a series of 15 pelvic aneurysmal bone cysts (9 boys and 6 girls) in children and adolescents who were reviewed with an average follow-up of 50.3 months. Pain and limp were the main symptoms. Four patients had no treatment after the open biopsy. Eleven patients were treated with curettage. Preoperative selective arterial embolization was performed in three cases before curettage. Two recurrences were noted after curettage; recurrences were treated successfully with further curettage. As a result, the authors recommend curettage; more aggressive operative intervention does not appear to be indicated. No major intraoperative vascular complications occurred. Spontaneous healing in a few cases (even in active or aggressive lesions) argues for clinical and radiologic observation after biopsy when possible. In case of a propitious evolution, observation must be continued and surgery might be avoided, but if the lesion increases, treatment must be proposed.