This study deals with the evaluation of free radical scavenging capacity of aqueous and ethanolic extracts of rhizome of Cyperus rotundus by their ability to scavenge DPPH, nitric oxide, hydroxyl radical and exhibit reducing power. Both extracts showed effective free radical scavenging activity. Compared to aqueous extract, ethanolic extract has shown better activity. The results support its extensive usage in various diseases. The main basis for this use seems to be its role as a rich source of natural antioxidant which protects the body from various oxidative damage.