PURPOSE: The purpose is to evaluate the effectiveness of open reduction and internal fixation in comminuted subtrochanteric fractures caused by high energy trauma at a non-osteoporotic young age. MATERIALS AND METHODS: Of all cases of subtrochanteric fractures caused by high energy trauma under 60 years old from February 2000 to February 2004, we analyzed 16 patients who had severe comminuted fractures (Seinsheimer classification type IV, V). The mean age is 43.5 (31~54) years old. Mean follow-up period was 22 (14~38) months. We tried to reduce anatomically as much as possible and fixed firmly using a compression hip screw in all cases. Additional procedures such as interfragmentary screw fixation, cerclage wiring or lateral stabilization plating were performed in 13 cases. Bone grafting was performed in 8 cases. We evaluated bony union rate, time to union, status of reduction, varus deformity and rate of implant failure using a simple X-ray. We also analyzed the clinical result using the Harris hip score including range of motion, pain and limping gait, so on. RESULTS: In all 16 cases, bony union was achieved and the mean time to union was 24 (20~32) weeks. There was no intra-operative complication. Postoperative complications such as loss of reduction, varus deformity, implant failure or infection did not occur. Clinically, the Harris hip score was 98.9 (97~100) points. CONCLUSION: Optimal open reduction and firm internal fixation with or without additional fixation was thought to be a recommendable method of treatment for comminuted subtrochanteric fractures of the femur caused by high energy trauma at a young age.