The aim of this study was to examine the possible antioxidant activities of wild Panax ginseng leaf extract intake in streptozotocin (STZ)-induced diabetic rats (WGLE). Initial blood glucose levels increased abruptly after streptozotocin injection. After 4 weeks of WGLE supplementation, blood glucose levels were lower in animals fed 40 mg/kg (266 mg/dL) and 200 mg/kg (239 mg/dL) than those in no-WGLE fed diabetic rats (464 mg/dL). The concentration of blood TBARS, which are considered the main products of glucose oxidation in blood, was also lowered by WGLE supplementation. These results indicate that WGLE supplementation is involved in suppressing a sudden increase in blood glucose levels and a consequent decrease in TBARS levels in diabetic rats. TBARS levels in the liver, kidney and spleen of WGLE-fed diabetic groups were also significantly lower than in the control diabetic group indicating that oral administration of WGLE effectively suppresses lipid peroxidation that occurs in the organs of diabetic rats. Antioxidant activities of WGLE supplementation further extend in suppressing activities of antioxidant related enzymes, such as glutathione peroxidase (GSH-Px), catalase (CAT) and superoxide dismutase (SOD), in organs of diabetic rats. These results confirm the effectiveness of WGLE supplementation in detoxifying free radicals that are produced excessively in diabetic-induced complications.