Nanoparticles have many characteristics that make them suitable for biological and medical applications. Uptake of these nano particulates into animals and humans bodies through different routes may exhibit potential side effects. Titanium dioxide (TiO2) is a common additive that is increasingly used in consumer products, food, pharmaceutical dosage forms and cosmetic articles. In this study, the effects of oral administration of TiO2 nanoparticles (500 mg| kg .bw) for 60 days were investigated on kidney function and histopathological changes. The body weight gain and kidney/body weight ratio showed no significant changes in comparison with the control group. There was a significant decrease in total thiol levels in kidney homogenate, the biochemical changes were supported by histopathologicalultration. In conclusion, the data shows that the oral administration of TiO2 NPs may lead to renal toxicity in experimental rats.