: The aim of the study was to investigate potential influence of placental tumors on fetal outcome. The study comprised 10 cases of placental tumors. The analysis included the sonographic assessment of the tumor, signs of fetal anemia, as well as signs of hemodynamic disturbances or heart failure, and intrauterine treatment. The fetal hemodynamic was examined on the basis of Doppler blood flow in the umbilical artery and vein, middle cerebral artery, and ductus venous. The evaluation of fetal heart included the measurement of heart size, blood flow through cardiac valves and the assessment of fetal heart function based on cardiovascular score. The fetal outcome was also assessed according to birthweight, gestational age at delivery, pH, Ap score at 5th minute, abnormal neurological development and the need of intrauterine therapy. Ten cases of placental tumors were prenatally detected from 1999 to 2011. Among them 7 cases of hypoechogenic, non-vascularized cysts were identified and these neither effected the hemodynamics nor complicated fetal outcome. The vascularized tumors (chorioangioma) were the cause of severe anemia and hemodynamic disturbances and these led to fetal cardiac heart failure. In all cases of vascularized tumors from 2-3 intrauterine transfusion were performed. Rich vascularized tumors (chorioangioma) may cause hemodynamic disturbances and fetal heart failure. This may require intrauterine treatment and may result in abnormal fetal outcome and neurological development.