Ocimum sanctum leaf extracts have been reported to augment insulin secretion in perfused pancreas, isolated islets, and BRIN-BD11 cells, as well as to decrease postprandial blood glucose levels in diabetic rats by retardation of carbohydrate digestion and absorption. In this study, the glycaemic, lipidemic, and platelet aggregation effects of the ethanol extract of the O sanctum leaves were evaluated in streptozotocin-induced type 2 diabetic rats. O sanctum significantly decreased serum glucose (p<0.01) and fructosamine (p<0.01) by 25% and 14%, respectively in 28 days of oral administration, the extract lowered serum cholesterol (p<0.01) and triglyceride (p<0.01) levels by 29% and 26%, respectively, and increased HDL cholesterol by 18% (p<0.05). O sanctum significantly reduced NEFA level by 50% (p<0.01), and platelet aggregation was decreased by 21% (p<0.05). Body weights were unchanged, and, over a 24-hour study period, there were no variations in food intake, water consumption, urination, or defecation. In conclusion, beyond its blood glucose-lowering effects, ethanol extract of O sanctum leaves lowers atherogenic lipids and decreases platelet aggregation. O sanctum is, therefore, a useful addition in controlling diabetes and its complications.