Atrial arrhythmias are the most common complication of cardiac surgical procedures today. Because of the additional hospital costs associated with these arrhythmias, owing to increased use of antiarrhythmic medications, diagnostic studies, and prolonged hospitalization, this subject continues to draw the interest of cardiac surgeons, cardiologists, insurance companies, and hospital administrators, among others. Despite many clinical studies, there is still no consensus regarding the best prevention strategy for these arrhythmias. We recently reviewed our experience with these arrhythmias, with the intent of identifying risk factors for the development of these arrhythmias and identifying any associated, potentially adverse, outcomes. We found that the incidence of postoperative atrial arrhythmias has increased to more than 35% in recent years. Risk factors for the development of postoperative atrial arrhythmias include increasing patient age, preoperative use of digoxin, history of rheumatic heart disease, chronic obstructive pulmonary disease, and increasing aortic cross-clamp (ischemic) time. Among patients with postoperative atrial arrhythmias, there was an increased rate of perioperative stroke, increased frequency of ventricular arrhythmias, increased need for the placement of a permanent pacemaker, and prolongation of the intensive care unit and total hospital length of stay.