To determine the type and prognostic significance of the various temporal profiles of vertebrobasilar territory infarction, 39 consecutive patients were studied. The following profiles were identified: 1) coma from onset, 5 patients; 2) sudden onset followed by stabilization, 12 patients; 3) gradual onset reaching stabilization within 24 hours, 7 patients; 4) gradual onset with progression beyond 24 hours, 2 patients, and; 5) delayed worsening after stabilization, 13 patients. Patients in Group 1 and those with unstable courses, Groups 4 and 5, had poor outcomes with mortality of 100 and 27 percent, respectively. Mortality for Groups 2 and 3 was 5 percent. Overall, hospital mortality was 25.6 percent. Demographic data, risk factors, presenting symptoms and type of neurologic deficit, other than coma, had no correlation with mortality, degree of disability and long term survival. At follow up of 6 to 52 months, median 24, only 7 percent of the survivors had recurrent cerebrovascular events; 2 patients (7%) died due to nonvascular causes and 72 percent of patients re-examined (20 of 28) were either neurologically normal or had only minimal deficits.