It is difficult to predict survival of fetuses diagnosed prenatally with congenital diaphragmatic hernia. Some studies suggest that left heart underdevelopment is associated with poor outcome, but fetal echocardiographic variables have not been conclusively proven to be good predictors of postnatal survival. The authors reviewed detailed fetal echocardiographic studies in twelve fetuses with congenital diaphragmatic hernia. Ten echocardiographic variables, including left and right ventricular width, left ventricular volume, and left ventricular mass, were examined from a four-chamber view, corrected for gestational age, and compared with normal data. The results of this study showed no significant differences between survivors and nonsurvivors in the ten variables analyzed. Although left heart dimensions and left ventricular volume in fetuses with congenital diaphragmatic hernia were below the expected normal range, these results did not predict postnatal outcome.