In recent years, there has been a large quantity of attention toward the field of free radical chemistry. Free radicals reactive oxygen species (ROS) and reactive nitrogen species(RNS) are generated by our body by different endogenous systems, exposure to various physiochemical conditions or pathological states. A balance between free radicals and antioxidants is needful for proper physiological action. If free radicals overwhelm the body's ability to regulate them, a condition known as oxidative stress ensues. Free radicals consequently adversely change lipids, proteins, and DNA and trigger a number of human diseases. Hence application of external source of antioxidants can assist in coping this oxidative stress. Thus, the search for effective, nontoxic natural compounds with antioxidative activity has been intensified in recent years. The attendant review provides a brief overview on oxidative stress mediated cellular damages and role of dietary antioxidants as functional foods in the management of human diseases.