Asclepias curassavica. Linn, an erect, simple (or) much branched perennial herb with a somewhatwoody base, belonging to the family Asclepiadaceae. It has been reported to have multiplepharmacological effect of anti-inflammatory, cardiotonic, anticancer, anthelmintic and to treatpiles and gonorrhoea. It is to be expected that several activities might be related to a possibleantioxidant action from this plant. The hydro alcoholic extract of Asclepias curassavica was testedin vitro for its antioxidant activities, such as DPPH radical, nitric oxide radical, superoxide anionradical, lipid peroxidation assay, hydroxyl radical, reducing power, and total phenol content. Theextract exhibited scavenging potential with IC50 value of 8.7 µg/ml, 198.4 µg/ml and 21.7 µg/mlfor DPPH, nitric oxide and superoxide anion radicals. The values were found to higher than thoseof Vitamin-C, rutin, and curcumin, as standards. The extract showed 50% protection at the dose of134.2 µg/ml and 41.4 µg/ml in lipid peroxidation as well as deoxyribose degradation, thosevalues more to that of standard, vitamin E (IC50 values, 119.2 µg/ml and 32.5 µg/ml,respectively). The reducing power of the extract depends on the concentration and amount ofextract. Since a significant amount of polyphenol could be detected by the equivalent to 0.0495 µgof pyrocatechol from 1 mg of extract. It can be concluded that hydro alcoholic extract of aerial partof Asclepias curassavica could be considered as potent antioxidant, which makes it suitable for theprevention of human disease.