One hundred and eleven patients with severe left ventricular dysfunction (EF < or = 25%) underwent coronary bypass surgery between January 1984 and December 1994. The selection criteria were based on the measurement of an EF < or = 25%, LVEDP and CI. All patients had angina and 83 had signs of pulmonary oedema or episodes of congestive failure. Patients with valvular disease, left ventricular aneurysms, reoperations, surgery for arrhythmias and prior angioplasty, were excluded. The coronary disease usually involved all three vessels. Seventeen patients had lesions of the left main stem associated with lesions of the right coronary artery. The average number of bypass grafts was 2.6 +/- 1.6 per patient. The average duration of aortic clamping was 60 +/- 19 minutes. Operative mortality (first month after surgery) was 10 patients (9%). The operative risk factors were: gender, stage of cardiac failure, emergency surgery, LVEDP > 23 mmHg (p < 0.05), CI < 21/min/m2 (p < 0.05). The mean follow-up period was 42 +/- months (3 lost to follow-up). Late mortality was 42 patients. The one year actuarial survival was 88 +/- 5.3%, 76 +/- 9% at 3 years, and 56 +/- 18% at 6 years. Long-term functional results were related to: preoperative stage of cardiac failure (NYHA stage IV) and the association of raised LVEDP and low CI. Surgical results remained satisfactory, however, and the surgical indication was justified in selected patients despite severe left ventricular dysfunction in cases usually with stable invalidating or unstable angina, in the knowledge that myocardial deterioration is progressive in the medium-term with a high incidence of cardiac failure.