Dipeptidyl peptidase inhibitors, a promising group of antihyperglycemic drugs, inhibits the enzyme, DP P-4, that destroys GLP-1 and GIP and thereby increases the le vels as a result by which blood glucose levels fall . Sitagliptin, a newer gliptin acting as dipeptidyl peptidase-4 (D PP-4) inhibitor is used in the treatment of type2 D iabetes Mellitus, combined with diet and exercise to improv e blood glucose levels. Antioxidant property is an essential mechanism by which it reduces oxidative stress in D iabetic patients there by preventing further beta c ell damage and occurrence of microvascular and macrovascular c omplications. This study evaluates the antioxidant activity of Sitagliptin by its free radical scavenging activity using DPPH (2,2-diphenyl-1-picrylhydrazyl hydrate) assay. Various Concentrations of Sitagliptin (100 μ g/ ml, 200 μ g /ml, 400 μ g/ml, 600 μg/ml ,800 μ g/ ml, and 1 000 μg/ml) were evaluated for DPPH free radical scavenging and the following percentage of activity was observed 2.5% , 4.9%, 8.12%,15.54%, 23.3% , 35% respectively which shows considerable antioxidant properties apart fr om being an effective oral hypoglycemic agent.