The results of 104 patients with fractures of the femoral shaft treated, from 1969 to 1973 at the hôpital du Sacré-Coeur in Montreal, by insertion of a large Küntscher nail alone were compared with those in 70 patients whose femoral shaft fractures were treated, from 1960 to 1975 at the hôpital Notre-Dame in Montreal, with a small Küntscher nail and an autologous iliac graft. Use of a large Küntscher nail without bone grafting gave good results in the majority of patients. Excessive reaming, however, diminished the area of contact between the fragments and prolonged the healing time. Refracture occurred more often. The average length of time for consolidation in nongrafted fractures was found to be equal to the maximum time for grafted fractures (i.e., 16 weeks). A small Küntscher nail with an autologous iliac bone graft could be used safely in fractures of the lower third and in the subtrochanteric region of the femur. Grafting produces earlier healing and weight bearing. The hypertrophic callus protects against refracture.