Causes of death, with special reference to cerebral haemorrhage, among 240 patients with pathologically verified Parkinson's disease were investigated using the Annuals of the Pathological Autopsy Cases in Japan from 1981 to 1985. The leading causes of death were pneumonia and bronchitis (44.1%), malignant neoplasms (11.6%), heart diseases (4.1%), cerebral infarction (3.7%) and septicaemia (3.3%). Cerebral haemorrhage was the 11th most frequent cause of death, accounting for only 0.8% of deaths among the patients, whereas it was the 5th most common cause of death among the Japanese general population in 1985. The low incidence of cerebral haemorrhage as a cause of death in patients with Parkinson's disease may reflect the hypotensive effect of levodopa and a hypotensive mechanism due to reduced noradrenaline levels in the parkinsonian brain.