We report the case of an elderly woman with Alzheimer's disease, risk factors for vascular dementia, and atrium-ventricular blockade, who presented with severe agitation and psychosis. She was treated with aripiprazole and assessed with the Neuropsychiatric Inventory (NPI) over the course of 14 weeks. NPI scores showed a marked decrease in psychosis and agitation at week 4, and complete recovery at week 14, except for depression.