: The current study was framed to evaluate the anti diabetic activity of falvonoids isolated from the leaves and rhizomes of Rhus mysorensis. Anti diabetic effects of these flavonoids were screened using in vitro and in vivo models. The in vitro anti diabetic activity was screened using enzyme assay. The in vivo anti diabetic activity was screened in albino diabetic induced rats. The inhibition of α-amylase and α-glucosidase by the isolated compounds were found in concentration dependent manner. The high inhibition was found at 150 mg/mL concentration. Among the compounds screened, 2-(3,4-dihydroxyphenyl)-hydroxy-4H-chromen-4-one and 5,6,7-trihydroxy-2-phenyl-4H-chromen-4-one showed significant enzyme inhibitory effects. the fasting blood glucose levels are increased 0 hour to 7 days of treatment. Animals of the groups VII, VIII, IX, XIII, XIV,-hydroxy-4H-chromen-4-one and 5,6,7-trihydroxy-2-phenyl-4H-chromen-4-one at 100, 150, 200 mg/mL) significant reduction in the blood glucose levels after prolonged treatment (P<0.001). we noticed that compounds 2-(3,4-dihydroxyphenyl)-hydroxy-4H-chromen-4-one and 5,6,7-trihydroxy-2-phenyl-4H-chromen-4-one started to reduce the glucose levels significantly from 14 days of treatment was comparable to blood glucose levels of animals treated with standard drug glibenclamide.