Background: Anti-cyclic citrullinated peptide autoantibodies (anti-CCP) is a new serological test for the diagnosis of rheumatoid arthritis (RA). It is an enzyme immunoassay (EIA) for the detection of antibodies directed toward citrullinated peptides. Studies show this test has an improved diagnostic value compared to rheumatoid factor (RF). Objective: To determine the sensitivity and specificity of anti-CCP in patients with rheumatoid arthritis and other rheumatic diseases. Method: 227 serum samples for rheumatology clinics (Putrajaya, Taiping, and Ipoh Hospital) were tested for the presence of anti-CCP and rheumatoid factor (RF). These included 171 patients diagnosed with RA and 56 from other rheumatic diseases. Patient demographic data, clinical diagnosis, radiographic information and other laboratory data were obtained from the patients' clinical notes. Results: Anti-CCP antibodies were detected in 76.6% (131/171) patients with RA and 17.9% (10/56) patients with other arthritis. The sensitivity and specificity of anti-CCP reactivity at the optimal cut off values were 66.1% and 87.5% respectively. The sensitivity of anti-CCP was higher than that for RF (41.8%). However, the presence of either anti-CCP or RF improved the sensitivity to 76.2%. Conclusion: The detection of anti-CCP alone maybe useful in the diagnosis of RA. However, when used concomitantly with RF, it can improve the diagnostic ability significantly.