Intrapericardial teratomas are rare tumors usually occurring in early infancy. Such a case was diagnosed in a 20 week old fetus, with a lethal outcome. About fifteen cases of intrapericardial teratoma have been reported in the fetal period. They are usually symptomatic, with a more or less severe pericardial effusion, sometimes complicated by cardiac compression and/or hydrops fetalis. Prognosis of the prenatally diagnosed pericardial teratomas is more related to the occurrence of hydrops fetalis than to the behavior of the tumor itself. The main interest of sonographic ante-natal diagnosis consists of the possible improvement of hemodynamic consequences through in utero pericardiocentesis. Macroscopic and microscopic features of this cardiac tumor are similar to those of extrapericardial teratomas. Most tumors discovered in fetal period are mature and histologically benign lesions. Only one case showed immature components. The coexistence of a malignant component (germ cell or non germ cell tumor) has been described in the postnatal and adulthood.