The present study was carried out to assess the influence of sesame oil on blood glucose, lipid peroxidation, and status of antioxidants in normal and streptozotocin (STZ) diabetic rats. Diabetes was induced in adult female albino Wistar rats weighing 180-200 g by administration of STZ (40 mg/kg of body weight) intraperitonially. Both normal and diabetic rats were fed with a commercial diet containing 2% oil supplemented with 6% sesame oil for 42 days. Diabetic rats had elevated levels of blood glucose (322.61 +/- 9.49 mg/dL), glycosylated hemoglobin, vitamin E, thiobarbituric acid-reactive substances (TBARS), and lipid hydroperoxides and decreased levels of hemoglobin, vitamin C, and reduced glutathione (GSH). An increase in glucose-6-phosphatase and fructose-1,6-bisphosphatase activities and a decrease in hexokinase activity were observed in liver and kidney tissues. When diabetic rats fed with sesame oil were compared with diabetic rats, a significant reduction in levels of blood glucose (222.02 +/- 8.27 mg/dL), glycosylated hemoglobin, TBARS, and lipid hydroperoxides and glucose-6-phosphatase and fructose-1,6-bisphosphatase activities and an elevation in hemoglobin, vitamin E, and GSH levels and hexokinase activity were observed. Thus, sesame oil consumption influences beneficially the blood glucose, glycosylated hemoglobin, lipid peroxidation, and antioxidant levels in diabetic rats.