In past there have been many medicinal plants, which have been used in traditional medicines for their antidiabetic properties without any scientific support and pharmacological evidence. The present study was undertaken to evaluate the antihyperglycemic activity of the crude extracts of leaves of Holarrhena antidysenterica. The pet ether, chloroform and ethanolic extracts have been subjected to estimate the anti-hyperglycemic activity in alloxan-induced diabetic rats. Blood glucose levels were measured using the commercially available glucometer. Glibenclamide was used as a reference drug at a dose of 0.6 mg/kg. The antioxidant activity of the test samples was studied in the liver tissue of diabetic rats by measuring catalase and lipid peroxidation levels. The results showed that ethanolic extract possessed a significant antihyperglycaemic and antioxidant activity equipotent with the reference drug (glibenclamide), when evaluated in diabetic rats.