Chylopericardium after thoracic duct injury is a rare but serious complication of thoracic surgery with mortality rates above 50% without intervention. Complications of chylopericardium are malnutrition, immunosuppression, electrolyte derangement and tamponade. This case describes a 67-year-old male who developed chylopericardium after coronary artery by-pass grafting and was successfully treated with conservative therapy consisting of pericardiocentesis and a low fat diet. If conservative therapy fails, thoracic surgery is almost always effective.