Twenty acute segmental fractures of the femoral shaft were treated with closed intramedullary nailing. The severity of the soft-tissue damage and associated injuries necessitated careful preoperative care. The surgical technique and means of reduction are outlined. Follow-up of at least one year on all patients showed a 100 per cent rate of union with no infections. Major complications included splitting of the greater trochanter during nailing (one case) and an 11-degree valgus deformity (one case). Maximum shortening was 1.5 centimeters. Knee flexion averaged 135 degrees in these acute fractures. The results in this series indicate that closed intramedullary nailing is an excellent method of treatment for this difficult fracture.