Between Jan. 1976 and May 1987, Sixteen supracondylar fractures of the femur were treated by interlocking nailing. Of the 16 cases, 7 cases were intercondylar, 12 cases were segmental fractures of the femur, 4 cases were open fractures in the type of wound. 1. The simple supracondylar fracture involving the distal 9cm of the femur can be treated by interlocking nailing which makes firm fixation and allows early ambulation. 2. If the supracondylar fracture is accompanied with intercondylar fracture, careful reduction and transcondylar fixation by means of tibial bolt or cancellous screws are essential before the insertion of the nail. 3. The shape of the bent nail must be depended on the type of the fracture. If the nail is to be inserted into the anterolateral aspect of the distal fragment, the degree of bending of the nail is 400cm, and posteromedial is 110cm in radius. 4. The authors made several sagittal holes the at dorsum of the nail. So the screw can be easily inserted to the nail perpendicularly or obliquely, when the insertion of the screw through the transverse holes is difficult. 5. Of the 15 cases treated by interlocking nailing, 5 cases were excellent, 4 cases were good, 2 cases were fair, 4 cases were failure by schatzker assessment.