Pleural effusions are common after coronary artery bypass grafting (CABG) surgery and can be categorized by time intervals: perioperative (within the first week), early (within I month), late (2-12 months), or persistent (after 6 months). The perioperative effusions are usually attributable to diaphragm dysfunction or internal mammary artery harvesting and are typically self-limited. Early effusions are usually attributable to postcardiac injury syndrome and may require corticosteroid treatment. Although late effusions can have multiple causes, persistent effusions are attributable to trapped lung and often require decortication. Diagnostic thoracentesis should be performed for patients with large symptomatic pleural effusions or fever after CABG surgery. The range of management includes observation, therapeutic thoracentesis, corticosteroids, or decortication depending on the cause and course of the effusion.