Rheumatoid arthritis is a chronic inflammatory systemic disease of young or middle aged adults, characterized by destructive and proliferative changes in the synovial membrane, periarticular structures, skeletal muscle and perineural sheath. Eventually, the joints are destroyed, ankylosed and deformed. Therfore, the aim of treatment is to keep the inflammatory process at a minimum, thereby preserving the joint motion, maintaining the health of muscle supplying motor power about the joint and preventing secondary joint stiffness and deformity. Surgical treatment in rheumatoid arthritis has progressed and there have been advances in the relief of pain and increase in the range of motion. Among them the results of total knee arthroplasty (TKA) have improved steadily during the past decade due to refinements in design, fixation, and surgical technique. At orthopedic department of seoul national university hospital, we performed 31 total knee replacement in 18 patients who had suffered from rheumatoid arthritis during the period from Aug. 1982 to Dec. 1988. Following results were obtained. 1. Knee score increased from 37.8 to 76.9. 2. Tibio-femoral angle was corrected from 0.9° valgus to 5.3° valgus. 3. Conplications were peroneal nerve palsy in 3 knees, instability in 1 knee, tuberculous arthritis in 1 knee. 4. In 25 out of 31 knees, good functional results were obtained.