The results of treatment of femoral shaft fractures with interlocking compression nail, the third generation nail, were evaluated to determine the incidence of union of the fracture & clinical usefulness. Fifty-three femoral fractures that had been treated by interlocking compression nailing between February 1994 and March 1996 and had been followed for more than twelve months were included in this study. forty-eight cases were fresh closed fracture and five, fresh open fracture. The results were as follows 1. According to Winquist-Hansen classification, 25 cases were type I, 13 type II, 7 type III, 5 type IV, 3 type V. 2. Union occurred in 52(97%) of 53 femoral shaft fractures. The mean fracture union period was 18.1 weeks with a range of 10 to 32 weeks. 3. Postoperative complication were delayed union(5 cases), leg length discrepancy(2 cases) and nonunion(1 case). We concluded that interlocking compression nailing for femoral shaft fracture seems to promote the fracture healing process without conversion to dynamic intramedullary fixation.