Overproduction of free radicals, inconsistent with inactivating capacity of the naturally occurring antioxidants, leads to altered physiology and morbidity. The role of free radicals in normal physiological states like ageing and common health problems like burns, infertility and cancer or systemic diseases of the cardiovascular system e.g. atherosclerosis, hypertension, reperfusion injury as also disease of other systems (CNS, Immunity, endocrine anomalies) have been discussed. This review of available studies explores the role of antioxidants in minimizing the oxidative stress in various disease conditions like diabetes, cataract, inflammatory conditions, AIDS and mutagenic effects of reactive oxygen species.