Aneurysmal bone cyst is a benign but locally destructive lesion of bone. We present two cases of ABC in uncommon locations in two children. The first case concerns a 14 year old boy who had a mass located in the internal side of the talus. An ABC type V of Campanacci's classification is diagnosed. Complete curettage was carried out with a high-speed burr. We implanted an Orthofix external fixation with a mobil bottom bolster and distal pins located in the calcaneum. Case 2 concerns an ABC in the clavicle of a 9 years old boy. A selective arterial embolization (SAE) with polyvinyl alcohol was carried out. Curettage of the lesion and filling with a cortico-spongy graft were implemented. Two years later, both of the patients are asymptomatic. We believe that external fixation with a bolster is an efficient and valid alternative to traditional immobilization with a cast. The use of SAE also prevented profuse bleeding of the lesion during surgical procedure.