From a survey of randomized studies we wanted to elucidate the therapeutic gain and the risk of complications with coronary artery bypass grafting (CABG) and percutaneous transluminal angioplasty (PTCA) in stable angina pectoris. The following main conclusions emerged: Invasive revascularization was associated with increased survival (reduced frequency of cardiac death or myocardial infarction) exclusively in patients with three-vessel disease and/or left main lesion accompanied by a decreased left ventricular function. This group accounted for less than 10% of treated patients. With regard to survival, patients with one- and two-vessel disease were better off with conservative treatment. Relief of angina was achieved for a number of years in the majority of patients. Angina recurred earlier following PTCA than CABG. PTCA is considered less traumatic, but a ten times higher need of additional revascularization seems to eliminate this advantage. The frequency of serious complications (including the higher risk at re-revascularization) was > or = 10% after PTCA and > or = 7% after CABG.