Coronary artery vasospasm (CVS) is an important mechanism of myocardial ischemia and produces any of the manifestations of coronary artery disease from silent myocardial ischemia, to effort-induced angina and variant angina, to acute coronary syndrome including myocardial infarction or sudden cardiac death. The pathogenesis, characteristic clinical features, diagnosis, and treatment of CVS are summarized. Emphasis is placed on correct diagnosis of CVS using pharmacological spasm provocation test, either during coronary angiography or with echocardiographic monitoring of ventricular wall motion. Current underutilization of pharmacologic provocative test at the time of coronary angiography cannot be justified, as there is no evidence supporting that the incidence of CVS is declining. Physicians' vigilance for objective documentation of CVS is necessary for appropriate management of patients with various clinical presentations of ischemic heart disease.