In a prospective study risk factors for neurological complications were evaluated in 300 unselected patients undergoing open heart surgery due to coronary artery disease. Patients with combined procedure (aorto-coronary bypass graft and valve replacement) were excluded from the study. Six patients (2%) suffered from a neurological event in the early postoperative period. A strong risk factor is the age (65 +/- 6 years in the symptomatic group, 56 +/- 9 years in the asymptomatic group, p = 0.009, Student-t-test, double-sided). A certain tendency is seen in patients with carotid stenosis (17% in the symptomatic group, 5% in the asymptomatic group), in patients with a positive neurological history (17% in the symptomatic group, 1% in the asymptomatic group) and in patients with operative revision (33% in the symptomatic group, 4% in the asymptomatic group). No difference was seen in the risk factors sex, lesions of the middle cerebral artery and the ECC-time.