PURPOSE: This study was performed to evaluate the risk factors affecting the failure of fixation and to analyze the clinical and radiologic results after operation with using a sliding hip screw for treating OTA type A2 intertrochanteric fractures of the femur. MATERIALS AND METHODS: From January 2001 to June 2005, we reviewed the clinical records and the serial radiographs of 53 patients (OTA type A2 intertrochanteric fractures of the femur) who were treated with a 135-degree angled sliding hip screw. We analyzed the change in the neck-shaft angle, the sliding distance and failure of the sliding screw, according to the reduction of the lesser trochanteric fragment and the stability of the lateral buttress. RESULTS: Among 53 patients, there were 15 cases (28.3%) of failures to reduce the lesser trochanteric fragment. Losses of the lateral buttress were observed in 35 cases (66.0%). There were 8 cases (15.1%, 8/15) that failed radiologically, including cutting out of the sliding hip screw from a femoral head (3 cases), metal failure (1 case) and excessive sliding (4 cases). There were significantly differences for the changes of the angle of the neck-shaft, the distance of sliding and the length of penetration of the sliding hip screw, according to the reduction of the lesser trochanteric fragment and the stability of the lateral buttress. CONCLUSION: It is important to consider the reduction of the lesser trochanteric fragment and the stability of lateral buttress when treating OTA type A2 intertrochanteric fractures with using a sliding hip screw.