Background: Excessive generation of reactive oxygen species ( ROS) contributes to the process of progressive renal injury in a variety of clinical and experimental renal diseases. The present study was designed to test the hypothesis that treatment with vitamins decreases renal injury in chronic renal failure ( CRF). Methods: Forty male Sprague- Dawley rats were divided into 5 groups: group 1, control; group 2, 5/ 6 nephrectomy ( CRF); other groups 5/ 6 nephrectomy and injected vitamins ( E, A, D). After 8 weeks, urea, creatinine and renal tissue malondialdehyde ( MDA), glutathione ( GSH), nitric oxide ( NO) levels and superoxide dismutase ( SOD) activities were determined. Results: Renal tissue MDA levels were significantly lower in the control and Vit E groups compared to that of the CRF, Vit A and Vit D groups. GSH levels were significantly higher in the control group compared to that of other groups. However, GSH levels were significantly lower in the control group than those in the other groups. SOD activities of the control group were significantly higher than those in the other groups. SOD activities were significantly decreased in the Vit E group compared to the Vit A and Vit D groups. Tissue NO levels of control group were significantly increased compared to the other groups. Conclusion: According to this study, Vit E may at least in part prevent tissue injury by acting as a free radical scavenger. Copyright (C) 2005 S. Karger AG, Basel.