Aim: An augmented brain renin angiotensin system (RAS) activity has recently been shown to be involved in pathophysiology of Alzheimers disease.Drugs that act by manipulating RAS such as ACE inNbitom thus could have potential roles in preventing cognitive deterioration seen in AD and other forms of dementia.In the present study, antioxidant effect and choline acetyltransferase (ChaT) activity of low and high doses of three different ACE inhibitors were studied in scopolamineinduced amnesia model of dementia.