Periprosthetic fractures as a complication of hip arthroplasty are uncommon. However, the incidence has been increafed recently especially in cementless or press-fit arthroplasties. The need to achieve a tight fit of the prosthesis in the bone when using cementless component has led to increased risk of periprosthetic fractures. We have experienced periprosthetic fractures occurred in 52 cases(51 patients) among 814 hip arthroplastic from January 1990 to December 1997. Among the 52 cases of periprosthetic fractures, 5 cases were occurred in cemented femoral stem(5 cases among the total 236 cases of cemented femoral stem : 2.1%), and 47 cases were occurred in the cementless type of femoral stem(47 cases among the total 578 cases of cementless type of femoral stem : 8.1%). There were 43 cases of intraoperative fracture and the rest was occurred postoperatively. According to the Johannson classification, type I fractures were 28 cases, type II fractures were 20 cases, and type III fractures were 4 cases. In postoperative periprosthetic fractures, according to the Vancouver classification, type A fracture was 1 case, typeB 1 fractures were 4 cases, typeB2 fractures were 2 cases, and type C fractures were 2 cases. The accurate preoperative templating and prophylactic managemnet of the risk factors are important for reducing the incidence of periprosthetic fractures.