Six hundred and thirty individual serum samples from dairy sheep were tested for the presence of antibodies to Toxoplasma gondii using an indirect immunofluorescence antibody test (IFAT). The sampled animals came from 33 dairy herds representative of the southern area of the Tuscany region. Questionnaires exploring the management system were filled in by the veterinarian in charge of the herds. Using a cut-off of 1: 64, 214 animals (33.97%) were positive with a herd prevalence of 96.97%. Using a sensitivity and specificity of 80% and 95% respectively, the true prevalence was calculated as 38.62% (CI, 34.82%, 42.43%). In the multivariate statistical analysis, T. gondii seropositivity in sheep was significantly associated with herd size <300 (OR=2.046, CI=1.284-3.261), still water source (OR=1.514, CI=1.050-2.182), and access of cats to water given to animals (OR=1.585, CI=1.057-2.379).