The purpose of this study was to investigate whether vitamin E and selenium have a protective effect against small intestinal damage induced by radiation. Radiotherapy has a quite important role in cancer therapy. Yet the most important problem is cytotoxicity, which occurs in the applied tissues, depending on the radiation underwent. Pre-treatment with antioxidants has been known to have a useful effect against radiation damage. Wistar albino rats were divided into three groups. Group I: control group, Group II: Only single-dose administration of 1000 cGy radiation, Group Vitamin E and selenium were administered, followed by the administration of abdominal radiation. Light and electron microscopic examinations have revealed that administration of radiation caused degenerative changes on small intestinal tissue. Treatment with vitamin E and selenium seemed to reverse these effects. Biochemically, blood glutathione levels in the radiation group were found to decrease. Vitamin E and selenium were found to increase blood glutathione levels. These results indicate that antioxidant treatment prior to irradiation may have protected the small intestine against radiation-induced damage. Dietary vitamin E and selenium have a potentially protective effect on the small intestine of patients subjected to abdominal radiotherapy.