Subtrochanteric fracture of the femur are difficult to treat successfully. Although performing operative treatment, the incidence of mechanical complications is higher than other sites of long bones. Among many factors influenced management of subtrochanteric fracture, there are three more important factors which subtrochanteric area composed mainly of cortical bone, high concentration of stress, and influenced to surrounding large and powerful muscles. During the period of Nov. 1979 to Sep. 1981, 10 cases of subtrochanteric fracture of femur were treated by Zickel I-M nail at the Department of Orthopedic Surgery, College of Medicine, Korea University, and results were obtained as follows: l. Of 10 cases of subtrochanteric fracture, 8 cases occured in man, and 2 cases in woman. 2. Causes of 10 cases of subtrochanteric fracture were fall down or slip in 6 cases, and T-A in 4 cases. 3. Of 10 cases of subtrochanteric fracture, 2 cases were type I, 6 case were type II, and 2 cases were type lll by Zickel's classification. 4. There are no significant complieatioris except 1-2 cm shortening in the 2 cases of unstable comminuted intertrochanteric fracture. 5. Zickel nail is the good implant for rigid fixation of subtrochanteric fracture or subtrochanteric fracture extend to intertrochanteric area of the femur, if suitable indication.