Between January 1, 1977 and January 1, 1988, 220 patients over 70 years of age underwent coronary artery bypass surgery (CABG). Patients undergoing combined procedures, e.g. CABG and valve surgery, were not included. 39% of the patients were emergencies or urgent cases. Hospital mortality (less than 30 days after surgery or in hospital) was 7.7%. Mean hospital stay was 13.9 days. Postoperative morbidity consisted mainly of infections (n = 51), peri-operative infarction (n = 35), bleeding (n = 13), and renal failure (n = 13). 72% of the patients were in NYHA functional class I at the time of follow-up (mean 3.66 years postoperatively). Many factors were analysed as possible indicators for mortality, morbidity and postoperative functional class. Mortality was only related to the presence of pre-operative hypertension (P = 0.038), previous infarction (P = 0.056) and severity of coronary disease (P = 0.0458). Morbidity was weakly related to emergency procedures, previous infarction and severity of coronary artery disease (P less than 0.05). For postoperative functional class, no specific predictors were found.