Coronary artery spasm is the most frequent cause of ischemic heart disease without coronary atherosclerosis once other causes such as cardiomyopathy, arteritis, coronary ectasia, valvular heart disease or hypertensive heart disease are eliminated. We report 23 patients, 15 males and 8 females, whose ages ranged from 34 to 63 years, with a mean age of 47 years, with demonstrated angina pectoris and myocardial ischemia, whose cardiac cineangiography showed no signs of atherosclerosis. Nevertheless, a significant retardation in the progression speed of the contrast medium was observed, as indirect evidence of the increment in coronary resistance at the arteriole level. Coronary spasm was ruled out by administration of intracoronary ergonovine, and other causes of myocardial ischemia, such as muscular bridges, were also discarded. The clinical presentation of the ischemic heart disease was unstable angina (UA) in 21 patients and myocardial infarction (MI) in 2. In the UA group, 14 patients showed ischemic changes in the ECG while the pain lasted, and in 8 patients the changes were present during the stress test. In all of them, the stress test perfusion scan with thallium 201 showed myocardial ischemia. In the IM group, the diagnosis was based on the clinical findings, the ECG, the enzyme curve, and the technetium 99 cardiac scintigram. In the two-year follow-up the prognosis has been favorable with treatment based on calcium antagonists. Nowadays 18 patients are asymptomatic, four have stable angina and only one has unstable angina.