We have studied the effects of red wine on brain oxidative stress and nephropathy in streptozotocin (STZ)-induced diabetic rats. Diabetes was induced in Wistar rats with a single intraperitonally injection of STZ (50 mg/kg). Two weeks before and four weeks after injection, red wine was given orally in both normal and diabetic rats. Blood samples were taken from the neck vascular trunk in order to determine the glucose, triglycerides, total cholesterol, HDL-cholesterol (HDL-c), atherogenic index (AI), total protein, blood urea nitrogen (BUN), creatinine, insulin, lipid peroxidation products, reduced glutathione (GSH) and superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities. As well, we estimated the lipid peroxidtion, GSH and SOD, GSH-Px and catalase activities in brain and renal homogenates, and the excretion of albumin, proteins and glucose in urine over 24 h period. The administration of STZ caused significant increases in levels of glycosuria, proteinuria, albuminuria, glycemia, total cholesterol and AI, as well as in lipid peroxidation products in the brain, plasma and kidney, whereas it decreased the GSH content and SOD, GSH-Px and catalase activities. Treatment with red wine significantly prevented the changes induced by STZ. These data suggested that red wine has a protective effect against brain oxidative stress, diabetic nephropathy and diabetes induced by STZ, as well as it protects against hypercholesterolemia and atherogenic risk.