Objectives To investigate the potential value of antenatally determined total fetal lung volume (TFLV) by magnetic resonance imaging (MRI) in the prediction of the postnatal survival in congenital diaphragmatic hernia (CDH). Methods We examined fetuses with isolated CDH, in which MRI was used at 22–38 weeks of gestation to measure TFLV and assess intrathoracic herniation of abdominal viscera, that were liveborn after 30 weeks of gestation and had postnatal follow‐up until death or discharge from hospital. Regression analysis was used to investigate the effect on survival of gestational age at diagnosis, observed to expected (o/e) TFLV, intrathoracic herniation of the liver, side of CDH, gestational age at MRI, institution, year and gestational age at delivery. In 76 fetuses measurements of o/e TFLV and the lung area to head circumference ratio (LHR) were performed within 2 weeks of each other; in these cases o/e TFLV and o/e LHR were compared for their prediction of postnatal survival. Results In the 148 cases that fulfilled the entry criteria, multiple regression analysis demonstrated that significant predictors of survival were the presence or absence of intrathoracic herniation of the liver and o/e TFLV. The area under the receiver–operating characteristics curves for prediction of postnatal survival from o/e TFLV was 0.786 (standard error, 0.059; P < 0.001) and that from o/e LHR was 0.743 (standard error, 0.069; P = 0.001). Conclusions In the assessment of fetuses with CDH, MRI‐based o/e TFLV is useful in the prediction of postnatal survival. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.