Percutaneous transluminal coronary angioplasty, first performed in man in 1977, has been used increasingly in selected patients with angina pectoris due to coronary atherosclerosis. Patients with single-vessel coronary artery disease in whom the stenosis is relatively proximal, noncalcified, discrete, and tapered rather than eccentric are the best candidates for the procedure. Objective evidence of coronary insufficiency documented by scintigraphy or exercise testing allows objective follow-up. Patients must be candidates for coronary artery bypass graft surgery since a complication might require immediate operation. Clinical experience indicates that 60%-85% of patients chosen for coronary angioplasty can have their coronary stenoses successfully dilated. Symptomatic improvement occurs in almost 90% of successful dilatations. Follow-up studies have shown persistent vessel patency for more than 1 year. From 3% to 8% of patients have needed urgent coronary artery bypass graft surgery because of coronary insufficiency developing at the time of angioplasty. Mortality has been less than 1%. The initial favorable experience with coronary angioplasty indicates that it should continue to be evaluated. The limits of patient selection for the procedure and long-term results require further compilation of data.