Toxoplasmosis is an important zoonotic disease, which is caused by Toxoplasma gondii and is quite common in the world, found in all mammals including humans, poultry, and reptiles. It has been reported that; adult cattle do not have toxoplasmosis clinically, and it is possible they pass the parasite through the placenta to the fetus, and that some infected animals give birth to aborted or infected calves. This study was conducted to determine T. gondii seroprevalence in cattle of Siirt region in Turkey and seropositivity was determined in blood samples of 300 cattle by using ELISA. Results showed that 53 (18%) of the samples were seropositive, while 247 (82%) of the samples were seronegative. In addition, there was a significant difference between their average age groups.