Toxoplasmosis is a worldwide zoonosis caused by Toxoplasma gondii. Epidemiological surveys of T. gondii infection among livestock have great economical importance since this infection may cause abortion, growth retardation and neonatal mortality, with significant losses to breeders. In regard of public health, human infection can be acquired by ingestion of meat or milk in natura from infected livestock. The aim of this study was to assess the toxoplasmosis seroprevalence by indirect immunofluorescence antibody test (IFAT) in goats and sheep, in three counties of Rio de Janeiro state, from 10 different farms. The seroprevalences of anti-T.gondii IgG antibodies were 29.12% (60/206) in goats and 38.05% (137/360) in sheep, with titers ranging from 64 to 256, suggesting chronic infection. Association of each of the following epidemiological factors: female gender, adult age, extensive management system, grazing pasture and drinking lake water with seropositivity was observed only in sheep (p≤0.05). Improvement in breeding conditions may reduce the sources of infection in herds.