Free vascularized fibular autograft transfer to the defect area after wide resection of bone sarcoma is one of many biological reconstruction methods. We report on an 8-year-old girl with 7 years of follow-up treated for right femur osteosarcoma. A 26 cm long tumor was resected with clear margins. Because the length of one fibular autograft was shorter than the defect length, bilateral free vascularized fibular autografts were used in a vertical array on top of one another, and placed inside a fresh-frozen femoral allograft. The original length of the femur was maintained by this technique. J Pediatr Orthop B 22:52-58 (C) 2012 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.