PURPOSE: Although considered uncommon, periprosthetic fracture of the femur after hip arthroplasty is a serious complication that can be difficult to treat. Authors analyzed the types of fracture and modality of treatment. MATERIALS AND METHODS: Between Jan. 1983 and Dec. 1997, 17 cases of postoperative periprosthetic fractures had been treated at our hospital. These cases were followed up for an average of 58 (13-123) months. The fractures were classified according to Duncan and Masri classification. Three cases of type A, and 6 cases of type B1, 3 cases of type B2, 3 cases of type B3 and 2 cases of type C. The 3 cases of type A and 2 cases oftype B1 were conservative treatments. The 4 cases of type B1 were treated with open reduction and internal fixation with bone graft. The 3 cases of type B2 and 3 cases in type B3 were treated with long stem revision. The 2 cases of type C were treated with open reduction and internal fixation with bone graft. RESULTS: Bony union happened in all cases. The results according to Beals and Tower criteria were excellent in 12 cases, good in 3 cases and poor in 2 cases. CONCLUSIONS: The most frequent cause of periprostic fracture was trauma and other causes were loosening and osteolysis. Proper treatment method of periprosthetic fracture were important for stability of femoral stem