The study was conducted to detect the changes of oxidative stress parameters in cattle with Theileriosis. In this study, 20 cattle with tropical theileriosis, divided into 2 equal groups in according to their heamatocrit values, and 10 healthy cattle were used. The erythrocyte lipid peroxidation, plasma catalase, glutathione peroxidase, vitamin E, and vitamin C levels were determined in all groups cattle. The significantly differences between control and sick cattle was determined in oxidative stres parameters such as vitamin E (p<0.05), vitamin C (p<0.05), MDA (P<0.01), catalase (P<0.01) and glutathione peroxidase (P<0.001). In conclusion, the decrease of CAT, GSHPx, vitamin E, and vitamin C, and the increase of MDA in the cattle of theileriosis was determined that the indicator of oxidative stres during disease.