Eighteen patients with advanced giant cell tumors were treated with complete tumor resection and reconstruction using fresh osteochondral allografts. All patients had one or more of the following indications for tumor resection (as opposed to curettage): tumor recurrence, pathological fracture, or destruction of the subchondral bone plate. At the 4- to 16-year follow-up (mean 9 years), two grafts were revised to a second fresh graft because of fracture, one graft was converted to an allograft implant composite and two joints were fused because of infection. The functional results were assessed in 14 patients: 9 were good or excellent, 4 fair and 1 poor. We conclude that the fresh osteochondral allograft is a viable treatment alternative to prosthetic replacement in advanced benign, aggressive bone tumors.