Objective: To investigate the antidiabetic activity of hydro-alcoholic extract of Adina cordifolia (Roxb.) leaves (HAEACL) in alloxan induced diabetic rats at 250 and 500 mg/kg doses. Methods:Glibenclamide (10 mg/kg, s.c.) was used as the standard which produced a significant reduction in blood glucose levels. The blood glucose levels of experimental animals were determined at 0, 2, 4 and 6 h after treatment with the plant extract by using glu-oxidase peroxidise reactive strips and glucometer. Results: Treatment with HAEACL at 500 mg/kg dose decreased the blood glucose level significantly. However, the lower doses (250 mg/kg) of HAEACL produced a little decrease in blood glucose level. It showed that there was a dose dependent decrease in blood glucose level in the alloxan induced diabetic rats as compared to the control group. Conclusions: The present study shows that HAEACL possessed significant antidiabetic activity.