An extensive survey of stroke in Taiwan was carried out by members of the Neurological Society, R.O.C. (Taiwan). Of a total 7,355 acute stroke patients who were admitted to 26 teaching hospitals in Taiwan (January 1 through December 31, 1985), there were 3,949 (53.7%) patients of cerebral infarction (CI). There was little seasonal variation in CI occurrence. In 90.5% of CI patients, the age of onset was above 50 years. The male to female ratio was 1.51:1. Hypertension was noted in 2,648 patients (67.1%), diabetes in 1,030 (22.9%), and heart disease in 953 (17.4%). A previous history of one or more strokes was obtained in 24.6% of the CI patients, and transient ischemic attacks (TIAs) in 6.4%. The stroke onset during the ordinary activities was noted in 41.1% of the CI patients, during sleep in 12.8% and at rest in 9.9%. CI occurred most frequently in the morning hours (24.0%). The majority of patients (85.9%) underwent computed tomography which provided valuable information in making distinction between cerebral infarction and cerebral hemorrhage. Angiography was performed in 3.3% of the patients for visualizing the stenosis and/or occlusion of the intracranial and the extracranial vessels. The mortality rate for CI was 8.4%, and 49.4% of fatal cases died within the first week after onset. At the time of discharge, the stroke survivors were rated "recovered" in 10.8% of CI patients, "minimally disabled" in 26.3%, "moderately disabled" in 38.0% and "severely disabled" in 16.9%.