The case of a 31 year-old intravenous drug addict female patient with infection by the human immunodeficiency virus who had recurrent cardiac tamponade and who was diagnosed by pericardic biopsy as Kaposi's sarcoma is reported. The patient demonstrated involvement by cutaneous, mucosal, lymph node and probably pleuropulmonary Kaposi's sarcoma. Thoracic radiography, computerized tomography and echocardiography only showed the presence of pericardic effusion. Neither did the pericardic fluid obtained by pericardiocentesis provide any significant ethiologic data. Only the pericardic biopsy showed the typical lesions of Kaposi's sarcoma in this localization confirming diagnosis. This is the first case of pericardic Kaposi's sarcoma described in an alive patient and the difficulties of achieving the diagnosis of the cardiac involvement by Kaposi's sarcoma in AIDS patients are commented upon.