Increasing interest in biological activity of natural products outlined the necessity of isolation of bergenin from Peltophorum pterocarpum (P. pterocarpum) flowers. The present investigation comprises isolation of bergenin accompanied by important in vitro antioxidant assays such as DPPH, hydroxyl radical and nitric oxide scavenging activities, and ferric reducing power. The aim includes DNA protection and cleavage. Bergenin showed 4.47, 13.03, and 8.67% of DPPH, hydroxyl and nitric oxide scavenging activities at 100 µg/ml. It showed less ferric reducing power. The result indicates that bergenin is a mild antioxidant. Bergenin did not protect the DNA but it cleaved the DNA at a low concentration of 10 µg/ml. P. pterocarpum flowers are a cheap source of bergenin and they could be used as a natural antioxidant.