A case of an intrapericardial tumor diagnosed in utero at 26 weeks of gestation is presented. The prenatal echocardiographic follow-up of an incipient hydrops fetalis determined the management and the emergency surgical treatment. Histologically, the tumor appeared to be a benign teratoma, grade I. In the postoperative period an unexpected mediastinal tumor was found and removed later. This tumor also appeared to be a benign teratoma, grade 0. Both teratomas were independent and therefore primary.