Tuberculosis is responsible for approximately 4% of cases of acute pericarditis, 7% of cases of cardiac tamponade, and, in older studies, 6% of instances of constrictive pericarditis. However, in some nonindustrialized countries, tuberculosis is a leading cause of pericarditis. The diagnosis is based on demonstration of tubercle bacilli in pericardial fluid or on histologic section of the pericardium, or proof of tuberculosis elsewhere in a patient with otherwise unexplained pericarditis. Treatment consists of triple drug therapy for at least 9 months (isoniazid, rifampin, and streptomycin or ethambutol). Pyrazinamide can be used for the first 2 months, and the total therapeutic period can then be shortened to 6 months after culture conversion. Three months of corticosteroid therapy may be useful in patients in whom pericardial effusion persists or recurs despite the use of antituberculous drugs. Surgical resection of the pericardium is indicated for recurrent or life-threatening tamponade, or when there is persistent elevation of systemic venous pressure unrelieved by pericardiocentesis. As many as one third to one half of patients will eventually require pericardiectomy despite adequate drug therapy.