Despite advances made in the care of infants with congenital diaphragmatic hernia (CDH), survival remains poor. New therapy, such as extracorporeal membrane oxygenation (ECMO), is controversial but may improve survival. Thirty-two newborns with CDH were treated. Thirteen infants were treated with jugular vein-carotid artery ECMO after CDH repair elsewhere; six (46%) survived. Three of the remaining 19 were moribund shortly after birth and first received ECMO, then underwent repair; two (67%) survived. The other 16 underwent CDH repair; 8 of 9 (89%) recovered with conventional therapy, and 4 of 7 (57%) survived when ECMO was used after conventional therapy failed. Overall survival was 63%. Parameters with which physicians may attempt to predict survival or the need for ECMO after repair--such as A-aDO2, ventilatory index versus PCO2, presence of a "honeymoon period" (PaO2 greater than 100 mm Hg after repair), or oxygenation index--were unreliable. ECMO can improve survival in infants with CDH, probably through reversal of pulmonary hypertension. Presently available methods of predicting survival after CDH repair with or without ECMO are not accurate, and thus no infant should be excluded from repair or ECMO support.