A case of a 37 year old man with cardiac angiosarcoma causing recurrent pericardial effusion, who eventually died of cardiac rupture, is presented. The diagnosis was not established until the postmortem examination despite echocardiography, pericardiocentesis, and pericardial biopsy investigations. There is neither a specific manifestation that enables early recognition nor well proven effective treatment against this disease. Accordingly, the prognosis of cardiac angiosarcoma remains grave. A high index of suspicion is recommended in patients who present with unexplained pericardial effusion.