Abstract: Because of AFB1 effects on antioxidant enzyme activities and gene expression in kidneys have not been completely elucidated, the current study was designed to investigate the histopathological picture and activities and gene expression of antioxidant enzymes in kidneys of rats. Therefore, 20 rats were randomly divided into two equal groups. Rats in the first group served as control whereas rats in the second group received single i.p., dose of AFB1 (3 mg kg–1 b. wt.). Kidney damage and oxidative stress were observed in AFB1-intoxicated rats as indicated by a significant elevation in thiobarbituric acid reactive substances (TBARS), reduction of reduced glutathione (GSH) concentration, reduction in the activities of antioxidant enzymes namely catalase (CAT), total superoxide dismutase (SOD), glutathione peroxidase (GPX) and glutathione-s-transferase (GST) and down-regulation of gene expression of these antioxidant enzymes compare to control. Kidney sections of rats intoxicated with AFB1 showed swelling and vacuolar cytoplasm of distal tubules and desquamated distal tubular cells. In conclusion, AFB1 may exert its toxicity to kidney tissues by induction of lipid peroxidation and inactivation and down-regulation of gene expression of antioxidant enzymes.