Anecdotal reports of a mood-elevating effect in patients and improvements in the performance of memory tests in the clinic has led to investigations into the nootropic actions of angiotensin converting enzyme (ACE) inhibitors. A cognitive enhancing action for the ACE inhibitors has been demonstrated in a number of animals models of memory function. Neurochemical studies in animals have shown that angiotensin II acting via an angiotensin II receptor can inhibit the release of 3HAch from entorhinal cortex slices. Thus the ability of ACE inhibitors to facilitate cognitive processes may be related to reduced availability of angiotensin II. Lack of specificity of ACE inhibitors may be a limiting factor in the development of such compounds as cognitive enhancers. However, the recent development of selective antagonists for subtypes of the angiotensin II receptor may represent a novel approach for the treatment of cognitive disorders with an underlying cholinergic disturbance.