Oxidative stress is involved in the pathogenesis of atherosclerosis. A variety of antioxidants has been used in clinical studies, during the past few years, for the prevention and treatment of atherosclerosis. In small clinical studies it was found that both vitamins C and E may improve endothelial function in high risk patients. However, interventional trials have been controversial, with some positive findings, many null findings, and some suggestion of harm in certain high-risk populations. Therefore, treatment with antioxidant vitamins C and E should not be recommended for the prevention or treatment of coronary atherosclerosis. New antioxidant strategies are needed to clarify the exact role of antioxidant treatment in coronary atherosclerosis.