Alzheimer disease (AD) is a progressive neurodegenerative disorder characterized by a loss of memory and cognition, a decline in ability to perform activities of daily living, changes in personality and behavior, and an increase in resource utilization and medical care. The natural course of AD can be viewed as a gradual loss of independence divided into several stages (mild, moderate, and severe) that ultimately leaves the patient under the supervision of a caregiver. Acetylcholinesterase inhibitors are the most widely accepted and proven approach to the treatment of mild to moderate AD. However, management of patients with severe AD poses challenges to physicians because there are only limited treatment options for these patients. This article provides overviews of the natural history, current therapy, and diagnostic scales of AD, focusing on management of patients with severe AD. In addition, a brief summary of the existing clinical trials conducted in severe AD is presented.