Aims: We present the results of the PFC Sigma knee replacement at a mean follow-up of 2.75 years (range: 1 to 6 years). Clinician and radiographic evaluation was carried out using the American Knee Society Clinical Rating and Radiographic Scoring Systems. Patient outcome was assessed using the Oxford-12 and SF-12 health-status questionnaires. Methods: A consecutive series of 293 Total Knee Replacements (TKR) in 247 patients was followed prospectively between September 1996 and September 2002. Our series included 138 females and 109 males with a mean age of 73.2 years. We operated on 214 patients with osteoarthritis, 20 with rheumatoid arthritis, 12 with post-traumatic arthritis and on one patient with erosive arthritis. The patella was resurfaced in 36 knees. 11 patients died during the follow-up period. Results: Subjective patient satisfaction score was based on improvement in pain and functional status. It was marked as excellent in 183 knees, good in 75, fair in 26 and poor in 9. Active extension lag improved from a mean of 8.5 to 3.3 degrees and flexion from 98.5 to 107.1 degrees. The mean Oxford-12 score improved from 44.17 to 24.68 and the SF-12 from 30.05 to 34.99. Radiolucent zones were observed around 2 tibial components. Post-operative complications included wound-healing problems in 25 patients, wound infection in 12, cardio-respiratory in 12, DVT in 11, non-fatal PE in 3, resolved CPN palsy in 3 and 1 death. Prosthesis complications included stiffness in 31, chronic pain in 18 (4 CRPS) and instability in 3 knees. 13 patients underwent MUA and 6 arthroscopic excision of intra-articular adhesions. 2 prosthetic infections were confirmed by bone-scan. Revision surgery was undertaken in 3 patients, 1 for established infection, 1 patella replacement and 1 tibial insert exchange. Conclusions: The early results of the PFC Sigma Knee Replacement show a high degree of patient satisfaction with a low rate of serious complications. Survivorship analysis will be undertaken in the future.