From July, 1981 to December, 1988, 2431 percutaneous transluminal coronary angioplasties were performed on 1901 patients at the Heart Institute of São Paulo University Medical School. Seventy-six patients (4.0 per cent) underwent emergency coronary artery bypass grafting for failed angioplasty. The incidence of failed angioplasty was significantly higher in the impending myocardial infarction group (11.5 per cent) than in the angina group (4.8 per cent) and the acute myocardial infarction group (1.3 per cent). The mean age of the seventy-six patients was 54.4 years, and 54 patients were male. The operative mortality was 15.8 per cent, being 9 males and 3 females. Patients who had had a left main trunk dissection during angioplasty and those who were hemodynamically unstable following the failed angioplasty or who had had a cardiac arrest necessitating a cardiac massage during transportation to the operating room, had a higher mortality than patients in whom the failure occurred in other sites and those who were hemodynamically stable. Perioperative myocardial infarction was documented in 50 per cent of the patients. Patients who had had a cardiac arrest during the procedure had a higher rate of perioperative myocardial infarction than those whose preoperative hemodynamic condition was stable.