In this study, diabetic and non-diabetic male rats were given to sodium selenite (Se), lead nitrate (LN) and sodium selenite plus lead nitrate through gavage. LN caused to histopathological changes in small intestine tissue of nondiabetic LN and non-diabetic sodium selenite+LN groups. We observed that supplementation of sodium selenite has protective role on histopathological changes in small intestine tissue when the non-diabetic sodium selenite+LN group compared with non-diabetic LN group. In diabetic control group, histopathological changes in small intestine tissue were detected. Treatment of LN to diabetic rats caused seriously histopathological alterations. Sodium selenite treatment didn't show preventive effect on LN-induced toxicity in diabetic rats.