Most studies on the natural course of coronary artery spasm in patients with normal or nearly normal coronary arteries are based on medium-term follow-up in small populations. The present series includes 277 successive patients with a median follow-up of 89 months (range: 1 to 198 months). There were 206 men and 71 women whose mean age was 53.6 +/- 9.3 years. They were all assessed with coronary arteriography which revealed no stenoses greater than 50%. Spasm was confirmed during the coronary arteriography in 157 patients (56.7%), by a positive provocation test following the arteriography in 113 patients (40.8%), and by an electrocardiogram which showed Prinzmetal's variant angina in seven patients (2.5%). The majority of patients, 264 (95.3%) were treated with calcium channel blockers. At the end of this study: 35 patients (12.6%) were lost to follow-up; 20 patients (7.2% died) including 10 (3.6%) from cardiac causes; 18 patients (6.5%) experienced myocardial infarction in 11 of whom repeat coronary arteriography consistently demonstrated one or more significant stenoses (greater than 70%); 109 patients (39%) had persistent angina, in 52 of whom the severity (more than one episode per month) warranted repeat coronary arteriography which detected significant stenosis in 19 cases; 95 patients (34.3%) were asymptomatic. Multivariate statistical analyses showed that only predictors of major coronary events (death, myocardial infarction or angina requiring repeat coronary arteriography) were systemic hypertension or the finding of minor parietal irregularities on the initial coronary arteriogram. Conclusion. Despite treatment with calcium channel blockers, persistent or recurrent episodes of angina are frequently observed whereas complications such as myocardial infarction or death are rare.