We evaluated in a standard fashion 375 patients presenting with complaints of memory loss. Etiology of memory loss included senile dementia of the Alzheimer type (SDAT)-70%, vascular dementia-5%, mixed dementia (SDAT + vascular)-9%, and other etiologies-16%. Incontinence, transient symptoms, and gait disturbances occurred more frequently in vascular dementia than in SDAT. A history of cardiovascular disease and stroke was more common in vascular dementia than SDAT. Disturbances of gait, bradykinesia, and pyramidal tract findings were commonly seen in vascular dementia. Advanced technology aided diagnosis in only 6% of patients and CT was the most useful of such tests. An earlier age of onset was noted in those with a positive family history of SDAT. Duration of symptoms at presentation for SDAT patients varied inversely with the rate of progression of dementia 15 to 55 months later, suggesting that individuals who progress more slowly require more time to elapse before the family or patient realizes the need for medical attention.