Periprosthetic fractures after total hip arthroplasty or hemiarthroplasty are an uncommon complication. These fractures have problems of fixation of fracture and stability of the femoral component. Ipsilateral femoral fractures after hip arthroplasty occurred in 14 cases (11 patients) out of 510 hip arthroplasties performed between January 1985 and May 1996. These fractures occurred at an average of 3 years and 6 months after primary hip arthroplasty. These fractures were classified by Johansson classification. Nine fractures were treated with plate and cerclage wires. Four fractures were treated with skeletal traction. Bone graft was applied to the fracture site in 9 fractures which were treated by open reduction and internal fixation with plate and cerclage wires. Average follow up period was 21 months. The results were as follows. 1. All but three of the fractures had been developed by low energy trauma. Seven patients had osteolytic lesion around femoral component. Of the seven patients who had osteolytic lesions, six patients had periprosthetic fractures which connected with osteolytic lesions. We think that osteolysis is one of the important factors of the periprosthetic fractures after hip arthroplasty. 2. Four cases were treated by skeletal traction. One case had malunion. Progressive subsidence of femoral component was noted after union of fracture in 3 cases. Therefore these periprosthetic fractures which had an osteolysis and subsidence preoperatively should be managed with operative methods. 3. Nine fractures which had treated with plates and autogenous bone graft showed good hip joint function with stable femoral component. We think that stabilization of periprosthetic fractures with plates and cerclage seemed to be a good method for femoral fractures after hip arthroplasty.