A 72-year-old man with no symptoms was admitted to our hospital to investigate increased cardiothoracic ratio on chest radiography. There were no specific physical findings but the cardiac sound was weak. Electrocardiography showed low voltage in all leads. Thyroid function was within normal limits. Echocardiography revealed massive pericardial effusion. Pericardiocentesis was performed, and 1,800ml of gold paint-like opaque fluid was drained. Microscopic examination revealed cholesterol crystals, so the diagnosis was cholesterol pericarditis. Cytologic examination revealed no malignant cells, and no bacteria was cultured. Mycobacterium tuberculosis was not amplified using the polymerase chain reaction method of pericardial fluid. Further analysis showed reduction of apo-B in the pericardial fluid, suggesting involvement in the precipitation of cholesterol.