The present study was designed to investigate the invitro antioxidant activity of the hydro alcoholic extract of aerial parts of Cynodon dactylon (Family: Poaceae) which is used in folklore medicine for the treatment of various diseases. In vitro scavenging activity was assessed by different methods viz. DPPH radical scavenging activity, superoxide anion radical scavenging assay, nitric oxide scavenging assay, Ferrous chelating ability, hydroxyl radical scavenging assay, hydrogen peroxide scavenging activity and ABTS assay. In all the methods, the extract showed its ability to scavenge free radicals in a concentration dependant manner. Its antioxidant activity was estimated by IC 50 values. Superoxide anion radical scavenging assay showed a maximum inhibition of 93.33%. The free radical scavenging and antioxidant activities may be attributed to the presence of phenolic and flavonoid compounds present in the extract. Total Antioxidant capacity of the extract was measured using phosphomolybdenum method. Total antioxidant capacity equivalent of ascorbic acid was 172.39 mg/g of extract. The results obtained from this study reveal that the hydro alcoholic extract of Cynodon dactylon is rich in antioxidant components with several mechanisms of eliciting antioxidant actions which provide scientific basis for its use in folk medicine.