The records of 179 consecutive patients with acute carotid system cerebral infarction were studied to describe the temporal profile of the clinical events during the first week of the illness. Only those patients admitted to the cerebrovascular hospital service within 36 hours of the onset of the first symptom were included.The neurological status of 39%was stable (unchanged) at the end of seven days; 35%of the patients gradually improved. Nineteen percent had a progressing neurological deficit from the onset which stabilized within 48 hours of onset. Six patients (3%) had a remittingrelapsing course during the first 36 hours. Eight patients (4%%) had a significant late worsening, after 48 hours of stable or improving course.Mortality was 11% for the entire group. However, a high risk of death group was identified - the mortality was 41% for those patients who had any degree of decreased level of consciousness and hemiplegia at the time of admission.