The ten cases of metallic failure after I-M nailing & plate fixation who were treated at depart tment of orthopaedic surgery, Soon Chun Hyang University during nine years from June, 1974 to May, 1983 were clinically analysed. The survey as summerized as follows: l. Of the ten cases, six cases were seen the breakage of plate, two cases were the loosening of screw, one case was the brakage of nail & one case was the angulation of nail. Of the six cases of plates, two cases were DCP, three cases were ordinary plate & one case was Thornton plate. 2. Of the six cases who metallic failure occurred as plate failure, five cases were the femur fractures, one case was the tibia fracture. All case who metallic failure occurred as nail failure were ferumr fractures. Of the two cases of screw loosening, one case was the fermur fracture. One case was the tibia fracture. 3. The average interval between operation and metallic failure. 1) The plate breakage was 6.3 months. 2) The screw loosening was 7 months. 3) The nail breakage was 6 months. 4) The nail angulation was 8 months. 4. The causes of failure after internal fixation. 1) The causes of plate breakage. -1. Thin nail 2. Empty plate hole with slip down. 3. Inadequate support with bone loss. 4. Slip down (retrauma). 2) The causes of screw loosening. - l. Inadequate immobilzation in comminuted fracture. 2. Early weight bearing. 3) The cause of nail breakage..- 1. Thin nail. 4) The cause of nail angulation. -1. Abormal stress & overweight. 5. The metallic failure such as breakage, loosening and angulation of nail or plate can be prevented providing that the indications were thoroughly considered according to the level of fracture, type of fracture and degree of comminution, and that bony union process was observed accurately after I-M nailing and plate fixation.