Citrullinated proteins have been suggested to play a critical role in the pathogenesis of multiple sclerosis (MS). Anticyclic citrullinated peptide (anti-CCP) antibody is used in the early diagnosis of rheumatoid arthritis (RA). The objective of this study was to investigate the presence of anti-CCP antibody in patients with MS compared to RA patients and healthy controls. Fifty patients with MS (38 females, 12 males; mean age 36.72 +/- 8.82 years), 52 patients with RA (40 females, 12 males; mean age 40.87 +/- 10.17 years), and 50 healthy controls (32 females, 18 males; mean age 38.22 +/- 11.59 years) were included in this study. The levels of serum anti-CCP antibody were measured using an enzyme-linked immunosorbent assay (ELISA). The results of the study showed that anti-CCP antibody levels were significantly higher in RA patients versus MS or healthy controls (P < 0.001). Moreover, anti-CCP antibody was positive in 43 (83%) patients with RA, while it was negative in all MS patients as well as in all healthy controls. Also, no significant correlation was found between the anti-CCP levels and EDSS scores (r = -0.250). In conclusion, the results of this study did not support a positive association between serum anti-CCP antibody and MS.