The Argyreia cymosa bark extracts were subjected to in vitro antioxidant activity with different methods. The petroleum ether extract has shown antioxidant activity in ABTS, nitric oxide, hydroxyl radical (by p-NDA) and lipid peroxidation methods. The ethyl acetate extract has shown antioxidant activity in DPPH, H(2)O(2) and hydroxyl radical (by deoxyribose) scavenging methods.