Large bone allograft transplants have been successfully used to reconstruct skeletal defects created by tumor resections and failed arthroplasties, but little has been reported on their use in traumatic defects. Of approximately 500 allograft procedures done at the Massachusetts General Hospital from 1979 to 1988, 11 were done for restoration of traumatic bone loss. The average age of the patients was 30 (range 11 to 71 years), and the location of the defect was the tibia or femur in 10 of the 11 patients studied. Eight osteoarticular grafts (six hemicondylar and two total condylar) and three intercalary grafts were used for six open and five closed fractures. The time from injury to reconstruction averaged 17 months (3 to 96 months). Primary reconstruction was done in three cases and a salvage procedure in eight. Patients were assessed by the operating surgeon and a physical therapist using an evaluation system that considers function, life-style, and emotional acceptance. According to the system, nine patients had excellent or good results (six hemicondylar grafts, three intercalary grafts), one patient had a fair result (total elbow graft), and one patient had failure of a total condylar graft and subsequently required an amputation. This study suggests that large bone allografts are of value in reconstructing traumatic skeletal defects, especially those involving an articular surface in a young patient.