Purpose: To evaluate the clinical and radiological results of patients that underwent total knee replacement arthroplasty (TKRA) using a NexGen implant, and who were followed up for at least 2 years. Materials and Methods: Between July 1996 and June 2002, 100 knees in 67 patients, and followed up for at least 2 years following TKRA using a NexGen implant were retrospectively assessed for clinical and radiological results using the assessment standards of the Knee and Functional Score of the American Knee Society. Results: The average preoperative range of motion in patients with osteoarthritis and rheumatoid arthritis were (50-) and (70-), respectively, which had improved to (85-) and (90-), respectively, at the final follow up. In addition, the preoperative flexion contracture improved from (0-) and (0-) to (0-) and (0-) postoperatively. The results using the assessment standards of the Knee and Functional Score of the American Knee Society were improved from 62 (35-82) and 40 (0-70) to 95.8 (87-100) and 97 (70-100) in patients with osteoarthritis, whereas the patients with rheumatoid arthritis were improved from 53.8 (32-73) and 36 (0-50) to 95.1 (89-98) and 79 (55-95). As a complication, infection occurred in 2 cases; they were given a reimplantation. Conclusion: TKRA using a NexGen implant showed satisfactory improvement in pain relief and function, such as range of motion, as well as a lower occurrence rate of complications.