Reactive oxygen species (ROS) are induced by various endogenous and exogenous sources. Although almost all organisms are equipped with antioxidant defence systems, which are often inadequate to completely prevent oxidation stress-induced damage. Therefore, antioxidant supplements or natural products containing antioxidants may be used to reduce oxidative damage to the human body. Mushrooms have been part of the normal human diet for thousands of years and in recent times, the amounts consumed have risen greatly involving a large number of species. The main bioactive components of mushroom are phenolic compounds (phenolic acid and flavonoids), tocopherols, ascorbic acid, carotenoids. Polysaccharides are also important biologically active ingredients. The higher antioxidant activity is reflected by lower EC50 value. Austreus hygrometricus, Fistulina hepatica, Phellinus linteus, Pleorotus squarrosulus, Polyporus grammocephalus, Macrocybe gigantea show higher antioxidant potential. This review will discuss about ROS, their harmful effect on biological systems and antioxidant property as well as comparative antioxidant activity of mushrooms with special attention on some popular edible and medicinal ones. © RJPT.