The posterior stabilized condylar prosthesis is a modification of total condylar prosthesis. In 1978, it is designed to get more range of flexion and stability by the addition of a tibial polyethylene spine and a transverse femoral cam to provide function of the posterior cruciate ligament. Functional assesments by the Hospital for Special Surgery knee score and radiologic evaluation by the scoring system of American Knee Society was conducted. Between August 1982 and December 1985, 35 posterior stabilized prostheses were implanted in 26 patients. There was one death (one knee), abd five patients (six knees) were lost to follow up. Thus 28 arthroplasties in twenty patients were available for review. The average age of the patient was fifty five years (range, 26 to 75) and the average follow up period was six years and one month (range, 4 years 5 months to 7 years 9 months). The preoperative diagnosis was osteoarthritis in thirteen knees, rheumatoid arthritis in sixteen knees, post traumatic arthritis in four and other in one. The results was as follows:1. The average preoperative score was 42 points and the average post operative score was 8 points. 2. The average preoperative range of motion was 83 degrees and the average post operative range of motion was 10 degrees. 3. The flexion contracture was significantly improved from 25 degrees preoperatively to 3 degrees postoperatively. 4. The average preoperative tibiofemoral angle was varus 3.8 degrees and was corrected to algus 4 degrees. 5. According to the roentgenographic evaluation and scoring system of A.K.S., the average femoral angle and tibial angle were respectively 95 and 89 degrees on the A-P view. Femoral flexion was 14 degrees and tibial angle was 88 degrees on the lateral view. 6. Radiolucent zones were found in zone I, II, III, IV of one tibial component and in zone VII of the other tibial component. On lateral view, radiolucencies were found in zone I & II in each tibial components. In these cases, the radiolucencies were 1-2mm in width. No prosthesis hac a complete or progressive radiolucencies. 7. There were two superficial infections and two knees had deep infection. 8. Among the 20 patients responded "satisfactory" for this operation at the recent follow up. In conclusion, the posterior stabilized knee prosthesis was found to be a durable prosthesis with could be used in total knee replacement.