The AGC DA replacement has been used in our department for latest 3 years. 28 arthroplasties were performed on 26 patients. There were 20 women and 6 men of age from 29 to 74 (average 58,7). Bilateral knee replacements were performed on one man and one woman. 18 patients from this group were diagnosed as RA, 7 OA, and 1 LED. Primary knee replacement were done on 15 knees and secondary on 13 using AGC DA type. 26 patients were examined after half a year follow up according to Clinical Rating System of The Knee Society: 21 patients had good (75%), 6 satisfactory (21.4%) and 1 poor (3.6%) results. The results after secondary replacements were generally worse then primary ones. That was mainly due to limited ROM and walking ability. There were no early complications in wound healing although 11 patients had prolonged steroids therapy and 7 of them had also methotrexate combined with steroids given as a basic pharmacological treatment of systemic disease. There were two other complications. One patient with loosening of tibial part because of primary tibial component malpositioning. Reoperation and correcting position with longer stem was performed after 8 months. Second patient with extensor mechanism insufficiency caused luxation of prosthesis in flexion. Extensive exercises of extensor muscles solved the problem.