Debridement of the wound and immediate reamed nailing were performed on sixty-seven patients who had an open fracture of the femoral diaphysis. Forty-two of these patients were followed for a minimum of twelve months (average, twenty-three months). Using the classification system of Gustilo and Anderson, there were fifteen (36 per cent) Grade-I, nineteen (45 per cent) Grade-II, and eight (19 per cent) Grade-III soft-tissue injuries. All of the fractures healed within four months after injury. The average flexion of the knee was 127 degrees and that of the hip, 129 degrees. At least 90 degrees of flexion was achieved in both joints of all patients. Perioperative complications included loss of fixation in four patients (10 per cent), infection of the wound in two patients (5 per cent), a wound seroma in two patients (5 per cent), and thrombophlebitis in one patient (2 per cent). Late complications were angular malunion in three patients (7 per cent), limb-length discrepancy in three patients (7 per cent), external rotation malunion in one patient (2 per cent), and sciatic-nerve palsy in one patient (2 per cent). We concluded that immediate intramedullary nailing of an open femoral fracture can be accomplished safely, with an acceptable rate of complications, given thorough debridement of the wound, proper equipment, and an experienced surgical team.