One hundred fifty-five patients (121 men and 34 women) had an angiographically verified unilateral internal carotid artery (ICA) occlusion immediately after carotid bifurcation. The median follow-up period was 53 months. Forty-fire percent of the patients were fully independent in the activities of daily living (ADL), 22% required assistance in ADL, 11% were disabled, and 22% died within the follow-up period. The mortality rate was exceptionally low compared with previous series. A life-table analysis of the material gave a 94% probability of surviving the first year, 84% the third year, and 78% the fifth year. Young age was favorable in regard to functional recovery, but it had no influence on mortality. The condition at the acute stage was the most important clinical sign in predicting the prognosis. The prognosis of mortality and functional recovery was poorer for smokers than for nonsmokers, and hypertension had no effect on prognosis. Cerebrovascular disease and coronary heart disease were found to be the cause of death with equal frequency in this study.