Chylopericardium is a rare complication after cardiac surgery in children. We report a case of a recurrent chylopericardium complicating postoperative course in a 4-month-old child. Chylopericardium occurred after two separate operations 6 months apart. On both occasions, symptomatic cardiac tamponade required pericardial drainage. Differentiation of chylopericardium from simple postoperative pericardial effusion can be difficult. When chylopericardium is strongly suspected from previous history and patient background, prompt treatment, including pericardial drainage and dietary treatment, is warranted.