Objectives. The aim of the study was to assess long-term state and trait anxiety in cardiac surgical risk patients. Design. Thirty two patients with serum S100B > 0.3 mu g/l 48 hours after cardiac surgery with cardiopulmonary bypass were matched according to age, gender, type, date and length of surgery with 35 operated patients without elevated S100B. They completed Spielberger's Anxiety Inventory (STAI). Results. Patients with elevated S100B reported more state anxiety and trait anxiety. S100B was an independent predictor of both state and trait anxiety when controlling for perioperative variables. Conclusions. Patients with elevated S100B reported more anxiety 3-6 years after cardiac surgery. A postoperative blood sample can identify risk patients and facilitate appropriate follow-up.