The formation of reactive oxygen species is a physiological event in aerobic life. In case of infection, if the increased oxidant substances cannot be cleaned sufficiently by antioxidants, oxidative stress occurs. As a result, a number of pathological problems occur by damaging DNA, protein, carbohydrate and lipids. In biological systems, the balance between oxidants and antioxidants is important. In oxidative stress situations where the balance cannot be achieved sufficiently, support can be provided with the use of exogenous antioxidants. However, the molecular structure, route of administration and concentrations of these exogenous antioxidants are important. Otherwise, they may show a pro-oxidative effect. The present rewiev study makes a general overview of oxidative-nitrosative stress markers commonly used in infective clinical studies, antioxidant enzymes and parameters and antioxidant supplements.