Tuberculous pericarditis is a rare form of tuberculosis usually presenting as pericardial effusion or constrictive pericarditis. But rarely it may present as pericardial mass. We experienced a case of tuberculous pericarditis presenting as pericardial mass which was confirmed by open thoracotomy. The patient was 34-year-old female, who was previously treated for tuberculous pleurisy. She admitted for dyspnea on exertion and imaging study including chest CT and echocardiography showed pericardial mass. Open thoracotomy showed hard adhesive mass lesion around pulmonary artery and pathology showed chronic granulomatous inflammation with caseation necrosis. We report a rare case of tuberculous pericarditis presenting as pericardial mass. (Korean. J. Med 57:956-960, 1999)