Introduction: Titanium Dioxide (TiO 2 ) nanoparticles have potential risks to human health.They were able to enter brain to be detected in the cerebral cortex, cerebellum and hippocampus.Withania somnifera (WS) improve rotenone induced damage in cerebellum. Aim of the work:To study the effects of oral administration of TiO 2 nanoparticles on the cerebellum and the protective role of hydromethanoli...