The present studies were designed to evaluate supplemental grape seed extract (GSE) and vitamin E supplements on lipid peroxidation, on antioxidant systems and peripheral blood lymphocytes in rats exposed to x-rays. Three groups of rats were investigated: a control group (CG) received intraperitoneal (i.p.)physiological serum I mL/day (n = 10), i.p.; a vitamin E group (VG) received 50 mg/kg/day (n = 10); an i.p. grape seed extract group received 50 mg/kg/day (n = 10). Four weeks later, a 6 Gy radiation dose was given to the rats. Blood samples were taken 24h later after irradiation and lymphocyte, malondialdehyde (MDA), reduced glutathione (GSH), nitrate, nitrite, reduced ascorbic acid, retinol, beta-carotene and ceruloplasmin concentrations were analysed. The levels of GSH (p < 0.05), retinol (p < 0.001), fi-carotene (p < 0.05) and ceruloplasmin concentration (p < 0.001) in the GSE group were found to be higher than in the control group but the level of MDA (p < 0.001) and nitrite concentration (p < 0.05) in rats supplemented with GSE were found to be lower than in the control group.