Arsenic and phthalate are common contaminants found in the environment and concurrent exposure to these agents is highly probable. We therefore, investigated the effects of sodium arsenite (100 mg/l in drinking water) and di(2-ethylhexyl) phthalate (DEHP) (100 mg/kg body weight by gavage) individually and in combination on some oxidative stress indices in the rat. Exposure to either arsenite or DEHP resulted in a significant elevation of advanced oxidative protein products (AOPP) and lipid hydroperoxides (LOOH) concentrations in the plasma, liver, kidney and brain. The combined exposure reflected moderate additive effect on AOPP and LOOH levels in the liver and kidney respectively. The induced increases in the brain AOPP and LOOH contents were significantly more than either single treatment. Exposure to either toxicants alone led to pronounced reduction in the total antioxidative capacity (TAC) in the kidney and brain of the rats. Interestingly however, an antagonistic effect was produced by their interaction in the liver with a reversal of their individual effects. Paraoxonase activity was also drastically inhibited by all treatments in all the compartments studied. Coexposure to arsenite and DEHP displayed some specific interactive effects that are different from individual effects.