Arrhythmias are seen frequently in the early postoperative phase of coronary artery surgery. Ventricular ectopic beats and atrial fibrillation are the most common rhythm disturbances and they offer the greatest management challenges. Yet despite the lack of good clinical trial data, few new studies have been initiated and reported in recent years. Recent reviews have given a better picture of the epidemiology of atrial fibrillation, but as yet there is little of practical use for the clinician. Magnesium, which looks so promising in the treatment of patients with acute myocardial infarction, offers no preventative action against postoperative atrial fibrillation. Implantable cardioverter-defibrillators have brought a new “surgical” procedure to arrhythmia management, but with the development of transvenous systems, implantation of these devices may revert from the surgeon to the cardiologist. Implantable cardioverter-defibrillators have dramatically reduced interest in map-directed antiarrhythmic surgery, yet recent work suggests that abandoning such techniques would be inappropriate. Implantable cardioverter-defibrillators and map-guided surgery must evolve together; neither can replace the other.