PURPOSE: The purpose of this study is to compare the result between closed reduction and minimal open reduction in case of difficult reduction for subtrochanteric fractures fixed with intramedullary nail. MATERIALS AND METHODS: From Jan. 2001 to May 2005, 35 cases of subtrochanteric femur fracture treated by intramedullary nail and followed up for more than a year were selected out of 42 subtrochanteric femur fractures. Fielding classification and Russel-Taylor classification were used, and according to the fracture classification and method of reduction, the patients were grouped into closed or open reduction group. Fracture with minimal displacement or anatomical reduction was fixed by closed reduction, but in case of failed closed reduction or loss of reduction, minimal incision was made for open reduction and internal fixation, and the result between two groups were compared. RESULTS: In total of 35 cases, 15 cases were fixed by closed reduction and the rest 20 cases required open reduction. Operation time, amount of transfusion, total hospital days, partial weight bearing ambulation, and union time did not show significant differences between two groups. Ambulation and range of motion after the operation were satisfying in both groups. CONCLUSION: In treatment of subtrochanteric femur fracture with intramedullary nail, both closed and open reduction shows satisfying result, therefore when anatomical reduction is difficult to achiev by closed reduction, minimal incision open reduction and additional fixation is strongly recommended to obtain anatomical reduction and firm fixation.