Since 1971 the Orthopaedic Oncology Service at the Massachusetts General Hospital has performed 150 resections and allograft implantations for the management of mostly tumorous bone conditions. The procedures used cadaveric segments harvested from donors and stored at -80 degrees after exposure of the cartilage to 10% glycerol as a cryopreservative. Following resection of the tumor, the selected part was implanted and held with plates and screws or intramedullary rods, and the patients were observed closely for alterations suggestive of "rejection" (none was seen), presence of recurrences or metastases, functional status of the part, and relationship of complications to outcome. Of 91 patients followed up for two or more years, the grafts performed acceptably (excellent or good functional result) in 70% or more. The results were better in patients with low-grade tumors or benign conditions and in resections and transplantations that did not involve a joint. Complications were a major factor in determining outcome. In patients with skin sloughs (9 patients), infection (13.2%), and, to a lesser extent, allograft fracture (16.5%), the prognosis for retention of the graft and functional restoration was compromised, but nonunion or delayed union (11%) had little effect on end results. The program remains somewhat experimental, in that continued research is required to improve the predictability of bony revascularization and the viability of articular cartilage, and to avoid the problems associated with infection and fracture.