The diagnosis of dementia of the Alzheimer's type is defined by criteria from the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition and the National Institute of Neurologic, Communicative Disorders and Stroke-AD and Related Disorders Association. The latter divides diagnosis into definite, probable, and possible Alzheimer's disease (AD), with definitive diagnosis requiring pathologic confirmation. Both criteria require that other causes of dementia are excluded. A diagnosis of AD can be made with reasonably high accuracy using a combination of clinical criteria, neuropsychologic testing, and conventional CT and MR imaging. There is increasing emphasis on early recognition. Although current therapies produce a mild improvement in symptoms, there are several disease-modifying therapies on the horizon. This article reviews current standards in clinical diagnosis and management.