Intracoronary acetylcholine and intravenous ergonovine tests have been used to induce coronary artery spasm. To evaluate the usefulness of these provocative tests, acetylcholine and ergonovine tests were performed in 86 patients with normal or near normal coronary angiograms(clinically variant angina in 30, effort angina in 6, unstable angina in 5, myocardial infarction in 6, atypical chest pain in 39 patients). Acetylcholine was injected into each coronary artery in incremental doses (0.02, 0.05 and 0.1 mg into left coronary artery, 0.02 and 0.05 mg into right coronary artery) and ergonovin was given intravenously in graded doses of 0.05, 0.1 and 0.2 mg after completion of acetylcholine test. The results were as follow : 1) Among 86 patients, both acetylcholine and ergonovine tests were positive in 29 patients, both tests were negative in 50 patients, and acetylcholine test was positive but ergonovine test was negative in 7 patients ; The responses of acetylcholine and ergonovine tests were concordant in 92% of patients. The sensitvity and specificity of the acetylcholine test with reference to ergonovine test were 100% and 88% respectively. 2) In 7 patients(8%) acetylcholine test was positive but ergonovine test was negative, and this group may represent a spectrum of coronary spasm syndrome. CONCLUSION: Acetylcholine test is a safe and useful provocative test for coronary artery spasm, especially in the multivessel spasm.