Effect of Acacia catechu on intestinal absorption of glucose was evaluated using ethyl acetate extract of black catechu, a product obtained from the heart wood of the plant in an in vivo model in rats. Two doses of 250 mg/kg and 500 mg/kg of the test substance given orally produced significant reduction of glucose absorption when compared with the control group, Presence of tannins and flavonoids in the extract could be responsible for reduction in the glucose absorption by affecting the Na+, K+ ATPases, the pumps providing the driving force for glucose entry inside the intestinal epithelium.