Aqueous extract of Emblica officinalis was found to be a potent inhibitor of lipid peroxide formation and scavenger of hydroxyl and superoxide radicals in vitro. The amount of the fresh pulp needed to inhibit 50% of lipid peroxidation was 1, 000μg/ml in the Fe2+/ascorbate system and 640μg/ml in the Fe3+/ADP-ascorbate one. The concentration needed for 50% inhibition of superoxide-scavenging activity was 107μg/ml in the method involving photoreduction of riboflavin and 232μg/ml in the xanthine-xanthine oxidase method, and that for hydroxyl radical scavenging (deoxyribose degradation method) was 3, 400μg/ml. An indigenous drug preparation containing Emblica officinalis, used in India as a health tonic, was also found to have a potent antioxidant activity. The antioxidants present in Emblica officinalis were aqueous soluble, but partially extractable with ether, and were heat stable.