A 34 year old patient with prolonged unstable angina pectoris who did not respond to medical treatment is presented. In the course of three days he developed acute subendocardial infarction complicated by severe ventricular arrhythmias and cardiac arrest. Previously renovascular arterial hypertension due to important stenosis of the right renal artery had been diagnosed by renal arteriography. The precordial pain did not disappear with acute myocardial infarction. He presented acute postinfarction angina which required the use of vasodilator and beta-adrenergic blocking agents which did not alleviate his symptoms completely. Coronary arteriography performed a month after acute myocardial infarction demonstrated 99% stenosis of the left main coronary artery and 70% stenosis of the left anterior descending artery. During three days before surgery intraaortic ballon pumping was employed and the patient did not present precordial pain. The patient became asymptomatic after placing two aortocoronary vein grafts to the left anterior descending and circumflex arteries, and three months later blood pressure fell to normal after placing a right aorto renal graft. The poor prognosis of critical stenosis of the main left branch, its medical treatment and better evolution after surgery is discussed. The indications for intra-aortic ballon pumping in this type of patients and its use before surgery so as to be able to suspend beta-adrenergic blocking agents without risks are specified. Finally the surgical indications for renovascular hypertension are discussed.