During an 8 year interval, 184 patients with symptomatic single-vessel disease underwent coronary artery bypass grafting (CABG). There were no operative deaths and only one late cardiac death (5 year cumulative survival 97.9%). At 48 months mean follow-up, 91% are angina free or improved. The low incidence of perioperative and late myocardial infarction (MI) and the preservation of ventricular function seen on follow-up catheterization suggest that coronary bypass operations yield significant benefits in severely symptomatic patients with single-vessel disease. Evidence is presented which supports the idea that single-vessel coronary artery disease may be a unique manifestation of coronary atherosclerosis and not one stage in a continuum.