Atrial fibrillation (AF), a cardiac complication following non-cardiothoracic surgery, is more common and better characterized following cardiac surgery. Postoperative AF often prompts surgeons to consult hospitalists because it can be associated with serious surgical complications such as sepsis and venous thromboembolism. Although typically self-limited, AF can persist to discharge and can lead to an increased length of stay. Furthermore, conditions that are associated with AF contribute to increased mortality. The following module addresses the frequency and risk factors for AF, initial management and evaluation of postoperative AF, and the management of persistent postoperative AF that is still present at discharge.