To estimate the effect of oral iron on the intestinal function and oxidative redox status in piglets with dextran sulphate sodium (DSS)-induced colitis, fifty 21-day-old weaned piglets were randomly divided into five groups of ten each. The piglets received regular diet and water, or four diets with 0, 0.03, 0.2 or 1% FeSO₄·2H₂O and water with 4% DSS, respectively, for 10 days. We observed a markedly higher lactulose/mannitol (Lac/Man) excretion ratio and lower serum concentration of D-xylose in Fe 0.2 and 1% supplementated piglets than piglets on DSS alone, but not in Fe 0.03% supplemented piglets. The activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) significantly increased in the DSS group compared with the control group. Iron supplementation significantly decreased the activities of GPx and CAT, as was vitamin E content, but not SOD. Furthermore, excess iron significantly increased the production of malondialdehyde (MDA) and hydroperoxides (HP), in a dose-response related manner.