While angina pectoris is not uncommonly seen in hyperthyroidism, only rare case reports have proved that the myocardial ischemia was induced by coronary artery spasm. A 62 year-old man with a prior diagnosis of hyperthyroidism presented with repeated episodes of syncope and chest pain. The coronary angiogram showed normal coronary arteries. Severe diffuse spasm of both coronary was spontaneously induced and normalized after intracoronary nitroglycerin injection during the procedure of coronary angiography. For one year, he was on simultaneous antianginal and antithyroidal medicines with accomplishment of euthyroid state. He did not experience and anginal symptom for the last six months. The followup coronary angiogram performed 1 year later revealed a newly developed atherosclerotic lesion (about 50% stenosis in diameter) at the proximal left anterior descending artery. However provocative challenge test with intracoronary acetylcholine infusion failed to induce coronary spasm at the lesion. We report a case of coronary artery spasm associated with hyperthyroidism with a review of literatures.