Atrial fibrillation is the most commonly encountered arrhythmia after cardiac surgery. Although usually self-limiting, it represents an important predictor of increased patient morbidity, mortality, and health care costs. Numerous studies have attempted to determine the underlying mechanisms of postoperative atrial fibrillation (POAF) with varied success. A multifactorial pathophysiology is hypothesized, with inflammation and postoperative β-adrenergic activation recognized as important contributing factors. The management of POAF is complicated by a paucity of data relating to the outcomes of different therapeutic interventions in this population. This article reviews the literature on epidemiology, mechanisms, and risk factors of POAF, with a subsequent focus on the therapeutic interventions and guidelines regarding management.