Several studies provide evidence of an association between ischemic stroke and oxidative stress. Increased free radical formation together with a reduced antioxidant defense causes oxidative stress, that may play an important role in the pathogenesis of stroke associated neuronal injury. Several studies demonstrate increased oxidative damage to neuronal cells during cerebral ischemia and reperfusion. Antioxidant activity is known to reflect the altered redox balance of affected fluids, tissues or organs in acute ischemic stroke patients. Therefore antioxidant concentrations or measures of their activity have been used to estimate the amount of oxidative stress 1 . No single component of serum antioxidant complex could fully reflect the protective efficiency of blood, probably because of interactions that occur in vivo among different antioxidant compounds. Total antioxidant capacity considers the cumulative effect of all antioxidants present in blood and body fluids 2 . The aim of this study was therefore to measure changes in markers of antioxidant capacity (measured individually and total) following acute ischemic stroke.