Background: Toxocariasis is a zoonotic disease in human with worldwide distribution. Recently a relationship between toxocariasis and some autoimmune diseases has been considered. We aimed to investigate the seroprevalence of toxocariasis among multiple sclerosis (MS) and rheumatoid arthritis (RA) patients in comparison with healthy persons. Materials and methods: In the present study, 96 blood samples from MS patients, 50 blood samples from RA patients and 100 blood samples from healthy persons were collected. Collected samples were examined to detect anti-Toxocara antibodies using commercial ELISA kit. Results: The most of the participants in present study were females (69.1%). The average age of MS patient, RA patients and healthy persons were 37.5, 47.6 and 42.1 years old, respectively. Anti-Toxocara antibody was detected in serum of 8 out of 96 (8.3%) MS patients and 3 out of 100 (3%) healthy persons while anti-Toxocara antibodies were not detected in serum of RA cases. Conclusions: This study indicates that there was no significant correlation between IgG antibodies against Toxocara and variables such as gender and age. Based on the statistical analysis, there was no significant difference in Toxocara seropositivity between our control population with MS and RA patients.