A cross-sectional seroprevalence study of anti-Toxoplasma gondii IgG antibodies was performed in Jerusalem domestic and stray cats. An enzyme linked immunosorbent assay (ELISA) immunodiagnostic technique was used and results analyzed according to specific variables. The overall seroprevalence was 16.8%. After an initial high seroprevalence of 29.7% in kittens after 1-10 days of age, average positive titers dropped to a low of 7.0% at ages 11-60 days. Thereafter, average positivity increased continuously and was observed in 50% of cats more than 5 years of age (P = 0.0081). Toxoplasma seroprevalence was highest in the month of summer (25.1%, P < 0.0001); domestic indoor cats had a higher seropositivity (39.0%) than stray cats (14.2%, P = 0.0004). On average, cats from the mainly Arab inhabited areas of Jerusalem showed a higher positive seroprevalence to Toxoplasma than Jewish inhabited areas (34.1% and 16.0%, respectively, P = 0.0032). There were no significant differences in positivity rates between sexes, and between rates of those with the presence/absence of clinical symptoms similar to those of the disease.