Long-term prognosis of 90 patients with vasospastic angina without significant coronary artery disease (less than 50% reduction in luminal diameter) was examined for a mean follow-up period of 4 years. All patients had episodes of angina at rest and were treated with calcium antagonists. One patient developed myocardial infarction and 2 died suddenly during the follow-up period. In the patient with myocardial infarction, there was an abrupt worsening of angina prior to the infarction despite therapy with a calcium antagonist. One of the sudden death patients discontinued his calcium antagonist before his death. Of the sudden death patients, one had ventricular tachycardia and the other had a complete atrioventricular block during an anginal attack. The incidence of such serious arrhythmias was higher (p less than 0.01) in sudden death patients (2/2) than that in survivors (6/88). The treatment with calcium antagonists reduced the severity and frequency of angina in all patients. These results suggest that long-term prognosis of vasospastic angina without significant coronary artery disease is good as characterized by the low incidence of myocardial infarction and death and the favorable response to treatment with calcium antagonists.