PURPOSE: To evaluate the usefulness of proximal femoral nail in the treatment of intertrochanteric fracture. MATERIALS AND METHODS: The authors investigated the classificaton of fracture, operation time, the amount of intraoperative and postoperative bleeding, the amount of transfusion, postoperative ambulation status, bone union time and the complication among 45 cases who were treated with proximal femoral nail from Jan. 2001 to June 2002. RESULTS: The mean operation time was 116 minutes, and the amount of bleeding was 524 ml in average. The amount of intraoperative transfusion was 1.4 pints and that of postoperative transfusion was 1.1 pints. The complications were the intraoperative penetration of antirotational screw through the femoral neck in 2 cases, separation of the fracture fragment while inserting the nail in 4 cases, irritation of skin by retropulsion of antirotation screw in 2 cases, and penetration of antirotation screw through femoral head in 1 case. CONCLUSION: Proximal femoral nail was effective for the treatment of intertrochanteric fracture, however the surgeon should be carful about collision of the insertion handle against pelvis when the fracture line coincides with the insertion point of nail, especially in obese patients.