AIM: To evaluate the mortality rate, risk indicators for death, mode of death and symptoms of angina pectoris during 5 years after coronary artery by pass grafting (CABG) in relation to the preoperative left ventricular ejection fraction (LVEF). PATIENTS: All patients in western Sweden who underwent CABG without concomitant valve surgery and without previously performed CABG between June 1988 and June 1991. RESULTS: In all 1904 patients were included in the analysis, of whom 173 (9%) had a LVEF < 40%. Patients with LVEF > or = 40% had a 5-year mortality of 12.5%. LVEF < 40% was associated with an increased risk of death (RR 2.3; 95% cl 1.7-3.1). There was no significant interaction between age, sex or any other factor in terms of clinical history and LVEF. However, left main stenosis was a strong independent predictor of death among patients with LVEF < 40% but not in those with a higher LVEF. Patients with a low LVEF more frequently died a cardiac death and a death associated with myocardial infarction (AMI). Furthermore they more frequently died in association with congestive heart failure and ventricular fibrillation. Among survivors, symptoms of angina pectoris were similar regardless of the preoperative LVEF. CONCLUSION: Patients with a low preoperative LVEF have a more than two-fold increased risk of death during 5 years after CABG. Their increased risk of death includes cardiac death, death associated with AMI, congestive heart failure and ventricular fibrillation.