This study was carried out on sixty seven cattle, were forty four Theileria naturally infected cattle were diagnosed by using specific PCR, in addition to twenty three parsitologically free cattle, to evaluate the levels of antioxidant as well as different biochemical parameter with particular emphasis to the oxidative stress associated with Theileria infection in cattle. The obtained results showed there was a significant increase of mean value of the serum malondialdehyde (MDA) content in infected group compared to control group. On the other hand, there were a significant decrease in the mean value of whole blood catalase (CAT) activity, reduced glutathione (R.GSH), superoxide dismutase (SOD), glucose-6-phosphate dehydrogenase (G6PD) and nitric oxide (NO) concentration, total protein (TP) and albumin (Alb) in infected animals compared to control ones. It can be concluded that, Theileria infection in cattle plays an important role in the oxidative stress and associated with alteration in the levels of antioxidant enzymes as well as different biochemical parameters.