Adamantinoma of long bones is one of the rarest of malignant bone tumors; it is commonly located in the middle or lower third of the diaphysis of the tibia. A case with multiple occurrences affecting both the tibia and fibula is presented. En bloc resection with wide operative margins was performed, and a large tibial defect of 23 cm was effectively bridged by a revascularized free fibular flap. At 13 months follow-up, there was no sign of local recurrence or metastasis, and the patient was mobile.