Closed intramedullary reaming and nailing with a prebent cloverleaf nail provides a biomechanically ideal method of internal fixation for femoral fractures. With a properly trained surgical team and careful technical control, all the theoretical advantages of this technique can be realized. These include a very high union rate, minimal risk of infection, early mobilization, and shortened hospitalization. Reaming and insertion of the nail is performed through a starting point at the junction of the base of the femoral neck and trochanter. When reaming is done, the nail can be sufficiently large to withstand the forces of early ambulation, thereby allowing an early return to normal function for most patients. In comminuted fractures an intramedullary nail can be used as an internal splint. In conjunction with traction and/or guarded weight-bearing and/or cast-brace, this procedure can assure earlier and more anatomic union and earlier return to function. In 300 fresh femoral fractures treated with closed intramedullary nailing, most patients had early and nearly anatomic union with excellent knee function and maintenance of muscle strength. Significant complications included one non-union, which required renailing, and 19 malunions, most of which were relatively minor. Because the procedure is technically demanding and requires extensive special equipment, it is best suited for use in trauma centers.