Chylous pericardial effusion is an uncommon condition, and the treatment is difficult. We report a case of massive chylous pericardial effusion with tamponade in a 22-year-old man, managed successfully. Lymphoscintigraphy confirmed the communication between the lymphatic trunk and the pericardial space, which was surgically ligated. There are relatively few published reports of idiopathic chylopericardium, and its pathogenesis remains unknown. The most effective treatment is surgical ligation of the thoracic duct and creation of a pericardial window.