A neurological outpatient department studied 323 consecutive referrals for suspected dementia: 135 (41.8%) were not demented. Of the patients 12.1% had diffuse cognitive disorder; 10.2% circumscribed memory disorder; 0.9% other circumscribed cognitive disorder, 14.2% psychiatric disorder, and 4.3% were judged to be normal. Of the nondemented, 44.1% had a potentially treatable cause for their cognitive symptoms; in 27.4% it was depression. The total of demented patients was 188 (58.2%): 38.8% had primary degenerative dementia; 37.2% vascular dementia including combined degenerative and vascular dementia; and 23.4% had a specific cause. Patients with specific cause were significantly younger than those with other causes of dementia. A potentially treatable cause was found in 10.7% of all demented patients, the most common being metabolic disorders, meningioma, hydrocephalus, subdural haematoma, and depressive pseudodementia.