Abstract: The present investigation highlights the free radical scavenging activity of the plant Pisonia grandis by determining nitric oxide and 1,1diphenyl 2-picryl hydrazyl (DPPH) radical scavenging activity. The shade dried leaves were coarsely powdered and subjected to extraction by using methanol and fractionated with ethyl acetate and ethanol. The extract and its fractions were subjected to phytochemical screening and in vitro anti oxidant activity by various antioxidant assays. The antioxidant activities were compared with that of standards. From the results, it was suggested that the methanol extract and its fractions of the leaves of Pisonia grandis exhibited strong free radical scavenging activity in all the tested methods Ethanol fraction showed maximum scavenging of nitric oxide and DPPH radical at 1000 μg/ml. The Phytochemical test showed that the leaves contains flavonoids and tannins. Based on the results, it was concluded that the antioxidant activities may be due to the presence of Phenolic compounds such as flavonoids and tannins. The results justify that the therapeutic application of the plant in the indigenous system of medicine augmenting its therapeutic value. Keywords : Pisonia grandis Leaves , Antioxidant activity, free radical, nitric oxide, DPPH