Spontaneous coronary artery vasospasm is one of the important causes of acute chest pain syndromes. The diagnosis of diffuse multifocal spasm can be quite challenging and it could be easily mistaken for diffuse coronary artery disease. The use of intracoronary nitroglycerin can relieve spasm and reveal the real extent of coronary artery disease. Herein we present a case presenting with acute myocardial infarction due to severe coronary artery spasm that had even received fibrinolytic therapy. Multiple narrowing was shown during coronary angiography and the patient was scheduled for percutaneous coronary intervention (PCI). But after intracoronary (IC) injection of nitroglycerin, all of lesions disappeared completely and the diagnosis of coronary spasm was confirmed.