Chylopericardium is a rare entity that may be congenital in origin or secondary to surgical trauma, mediastinal lymphangiomas-hygromas, or radiation. Current treatment progresses from dietary medium-chain triglycerides and pericardiocentesis, to pericardial drainage, to thoracotomy with pericardiectomy and thoracic duct ligation. Between January 1986 and January 1989, we treated four children with chylopericardium: three secondary to mediastinal lymphangioma-hygroma, and one following cardiac surgery. The patients ranged in age from newborn to 16 years. All had signs of cardiac tamponade and three underwent initial pericardiocentesis or tube drainage. One 6-week-old infant with a mediastinal cystic hygroma developed chylopericardium following resection of the hygroma and responded to 9 days of tube drainage. The remaining children did not respond to repeated pericardiocenteses or prolonged drainage and underwent pericardial-peritoneal shunting with Denver shunts. The shunt was removed in 14 days in one patient. One patient had the shunt exteriorized for 8 weeks and one patient continues to use the shunt after 3 years. The chylopericardium resolved in each case without recurrence. Pericardial-peritoneal shunting provides a simple and effective alternative to prolonged pericardial drainage or thoracotomy in patients with chylopericardium of various etiologies.