A major complication in operative treatment of intertrochanteric fractures especially in osteoporotic and unstable cases is fixation failure. The authors analysed retrospectively 43 intertrochanteric fractures which were treated with 135 degrees compression hip screw at Hanil General Hospital from March 1986 to February 1990 and the results were as follows. 1. Two cases of lag screw penetration into the joint (4.6%) and eight cases of excessive collapse at the fracture site (18.6%) were found. 2. Complications occured only in unstable fracture. 3. Complications were found only in cases that the distal fragment was displaced medially and anteriorly to the proximal fragment. So the type of fracture and direction of displacement were considered as the major affecting factors.