The intramedullary nailing is one of the most available method in treatment of femoral shaft fracture. Since the development of Kuntscher naukl in 1940, new design such as Grosse-Kempf IM nailing became widely used by more applicable level of femoral shaft fracture. Therefore, complications of intramedullary nailing was rarely seen. The authors analysed complications in 7 cases of intramedullary nailing for treatment of femoral shaft fracture in Koryo General Hospital from Jan. 1991 to Jan. 1993., and the results were as follows; 1. The average age was 40.5 years and all patient's sex were male. 2. Among 7 cases, complications were delayed union in 4 cases, metallic failure in 2 cases and femoral neck fracture in 1 case. 3. Among 4 cases of delayed union, 3 cases treated by weight-bearing after dynamization and 1 case treated by bone graft after dynamization. 4. Metallic failure occurred in 2 cases, 1 case developed metallic corrosion in medullary canal, the other case developed metal failure at fracture. 5. Fomoral neck fracture in 1 case was treated by multiple Knowles' pins.