The Thompson and Austin Moore unipolar endoprosthesis and their derivatives have received widespread use in the treatment of conditions requiring replacement of the femoral head. However, pain, acetabular erosion, and protrusio acetabuli are serious late complications of the use of these prosthesis. To reduce the incidence of these adverse effects, bipolar endoprosthesis was introduced, with a low-friction bearing introduced between the femoral stem head and the acetabulum, allowing for the theoretic advantage of a low-friction bearing. The prototype of this design consisted of three parts: metallic cup, a separate ultrahigh molecular weight polyethylene liner, and a metallic femoral stem. The authors reviewed and analysed 50 cases of cementless bipolar endoprostheis (Harr-is-Galante porous hip prosthesis, straight stem), operated at the department of orthopaedic surgery, Keimyung University Dong San Medical Center from September 1983 to October 1990. The following results were obtained. 1. The intraoperative complications were 2 cases of calcar crack and 1 case of undisplaced femoral shaft fracture. The postoperative complication was only 2 cases of acetabular erosion. 2. The average Harris hip score was 48.5, preoperatively and 91.5, postoperatively in total 50 cases. The average postoperative Harris hip score was 91.9 in 24 cases of the lateral approach and 91.4 in 26 cases of the posterolateral approach. 3. Early clinical results of bipolar endoprosthesis using Harris-Galante porous hip system are excellent in 39 hips, good in 9 hips, and fair in 2 hips at average follow up of 32 months.