Isolated chylopericardium due to cystic lymphangioma of pericardium is a rare entity. We report a case of asymptomatic chylopericardium in a young male who presented with cardiomegaly. Echocardiography revealed massive pericardial effusion without tamponade. Pericardiocentesis yielded 1.25 L of tea-colored fluid which showed triglyceride level of 1723 mg/dL and cholesterol of 1021 mg/dL with a cholesterol to triglyceride ratio of <1, characteristic of chylous fluid. Lymphoscintigraphy using 99Tc demonstrated lymphatic leak around the heart region. Fusion of MRI images with lymphoscintigraphy was taken with a view of localizing the leak site; it demonstrated enhancement in the pericardial space. Surgery was done via right lateral thoracotomy. Thoracic duct was ligated above diaphragm and pericardial window created by anterior pericardiectomy. The patient had an uneventful recovery and was well after 6 months of follow up. Pericardial biopsy showed cystic lymphangioma of pericardium.