Pick's disease is a rare cause of dementia frequently misdiagnosed as Alzheimer's disease. Because patients with Pick's disease often present with psychiatric symptoms, the psychiatric aspects of this disorder are reviewed, as well as the pathology and epidemiology of the disease. Two case reports illustrate many of the clinical features of PD. A detailed examination of the psychiatric aspects of the disorder is followed by an elucidation of the many clinical differences between Pick's disease and Alzheimer's disease.