Background: Toxoplasmosis is probably one of the most common parasitic infections of humans. While infection of healthy adults is usually relatively mild, serious disease can result in utero or when the host is immunocompromised. Toxoplasmosis in diabetic patients may occur due to recently acquired acute infection or they may suffer from dissemination of reactivated latent infection. In the present study, the antinuclear antibody prevalence was tested to determine the possible relationship with Toxoplasma seroprevalence and clinical findings in type I diabetic patients. Methods: Toxoplasma gondii antibodies were tested serologically in 60 patients of type I diabetes mellitus and 60 controls using ELISA technique. Results: The seropositivity for anti-Toxoplasma IgG antibodies in the study groups was 45% in type I diabetes mellitus patients (group 1) and 23.3% in the control (group 2) with p value = 0.012 showing a statistically significant difference between groups, while only three patients of diabetes type1 group were positive for anti-Toxoplasma IgM with p value = 0.244 showing no statistically significant differences between the two groups. Results showed that only one patient of diabetes type 1 (group1) had positive ANA and one control (group2) had positive ANA. Thus, no correlation could be detected from such results. Conclusion: The study results showed a statistically significantly higher proportion (45%) of seropositivity anti-Toxoplasma IgG antibodies among type I diabetes mellitus patients compared to 23.3% among the control group, while there was no association could be detected between the studied groups regarding the ANA.