The present study was undertaken to investigate the effect of Coccinia indica, an indigenous plant used in Ayurvedic Medicine in India, on blood glucose, plasma insulin, cholesterol, triglycerides, free fatty acids and phospholipids and fatty acid composition of total lipids in liver, kidney and brain of normal and streptozotocin (STZ) diabetic rats. Oral administration of the ethanolic extract of Coccinia indica leaves (200 mg/kg body weight, CLEt) for 45 days to diabetic rats decreased the concentrations of blood glucose, lipids and fatty acids, viz., palmitic, stearic, and oleic acid whereas linolenic and arachidonic acid and plasma insulin were elevated. These results suggest that CLEt exhibits hypoglycaemic and hypolipidaemic effects in STZ induced diabetic rats. It also prevents the fatty acid changes produced during diabetes. The effect of CLEt at 200 mg/kg body weight was better than that of glibenclamide.