Oxidative stress was defined as corruption of balance between oxidant-antioxidant states in favor of oxidants. In this study, it was aimed to determine oxidative stress in naturally infected dogs with Babesia vogeli. The 8-hydroxy-2'-deoxyguanosine (8-OHdG), nitric oxide (NO) and total antioxidant capacity (TAC) levels in the sera were analyzed by ELISA. 8-OHdG levels increased in B. vogeli infected dogs compared to control group (P<0.05). Also, NO levels increased while TOC levels decreased in B. vogeli infected dogs but these variations were not found as statistically important (P>0.05).