Alzheimer disease (AD) is a diagnosis of inclusion based on patient history, physical examination, neuropsychological testing, and laboratory studies; however, there is no definitive diagnostic test for AD. Early recognition of AD allows time to plan for the future and to treat patients before marked deterioration occurs. Effective treatment requires monitoring of symptoms, functional impairment, and safety, and the use of multiple treatment modalities including pharmacotherapy, behavioral management, psychotherapies, psychosocial treatments, and support and education for families. Pharmacotherapeutic agents available for AD only provide symptomatic relief. The cholinesterase inhibitors, tacrine and donepezil, are effective in improving cognition, delaying nursing home placement, and improving behavioral complications in some patients. Other cholinesterase inhibitors are in development, as are other cholinomimetic agents such as muscarinic and nicotinic receptor agonists. Symptomatic treatments are available for the psychiatric manifestations of AD. Anti-inflammatories, antioxidants, neurotrophic factors, and other agents are promising new treatments for the future.