From 1987 through 1990, 34 acute Supracondylar femoral fractures in 33 patients were treated with an interlocking closed-section intramedullary nail inserted retrograde into the femur through the intercondylar notch. Follow-up data of at least five months were available for 25 of these fractures. The patients suffered injuries more extensive than comparable patients reported in the literature. All fractures healed clinically and radiographically. The average arc motion at the most recent evaluation was 100°. The average operative time was 156 minutes and the average estimated blood loss was 224 ml. Complications related to this treatment were successfully resolved. The genucephalic nail is a good treatment for Supracondylar femoral fractures.