Abstract: This study evaluates the seroprevalence of bovine toxoplasmosis in Fars province, Southern Iran. From March 2004 to April 2005, 588 bovine serum samples were randomly provided from 15 cattle slaughterhouse of 15 cities and towns in Fars province, Southern Iran that were divided into 5 districts including the central, Northern, Southern, Eastern and Western parts. Indirect Fluorescent Antibody Test (IFAT) was used to determine the antibody titer. The seroprevalence of toxoplasmosis was 20.24% (119 cattle) while the rate of seropositiveness in 1/16, 1/32, 1/64 and 1/128 dilutions were 15.31% (90), 3.74% (22), 0.85% (5) and 0.34% (2), respectively. The highest prevalence was in Eastern (23.33%) and Central parts (22.73%) and the lowest (2.33%) was noticed in Northern region of the province. The highest prevalence (37.5%) was observed in Mamasani. However, the lowest prevalence (zero) was found in Abadeh, Marvdasht, Arsanjan and Firouzabad cities. So, control measures such as environmental health education of veterinary personnel and standardization of techniques and hygiene in bovine breeding seem necessary to prevent transmission of the infection to human.