['Accurate and validated predictors of outcome for infants with congenital diaphragmatic hernia are needed. Score for Neonatal Acute Physiology-II has been validated to predict mortality in newborns. We investigated whether Score for Neonatal Acute Physiology-II scores in congenital diaphragmatic hernia could predict mortality, need for extracorporeal membrane oxygenation (in patients born in a center with extracorporeal membrane oxygenation availability), and development of bronchopulmonary dysplasia (oxygen dependency beyond 28 d after birth) in survivors.', 'Data were obtained from a prospective, multicenter randomized controlled trial of initial ventilation strategy carried out by the Congenital Diaphragmatic Hernia EURO Consortium (NTR 1310).', "ICUs of level III university children's hospitals.", 'Congenital diaphragmatic hernia infants without severe chromosomal anomalies or severe cardiac anomalies born between November 2008 and December 2013.', 'Randomization for initial ventilation strategy (high-frequency oscillation/ conventional mechanical ventilation.', 'Logistic regression analyses were used to evaluate associations between Score for Neonatal Acute Physiology-II and outcome parameters. Of the 171 included patients, 46 died (26.9%), 40 of 108 (37.0%) underwent extracorporeal membrane oxygenation, and 39 of 125 survivors (31.2%) developed bronchopulmonary dysplasia. In nonsurvivors, the median Score for Neonatal Acute Physiology-II was 42.5 (interquartile range, 33.5-53.8) and 16.5 (interquartile range, 9.0-27.5) in survivors (p < 0.001). Score for Neonatal Acute Physiology-II also significantly differed between extracorporeal membrane oxygenation and non-extracorporeal membrane oxygenation-treated patients (p < 0.001), and survivors with and without bronchopulmonary dysplasia (p < 0.001). Multivariable logistic regression analyses adjusted for hernia side, liver position, ventilation mode, gestational age, center and observed-to-expected lung-to-head-ratio showed that Score for Neonatal Acute Physiology-II was associated with mortality (odds ratio, 1.16 [1.09-1.23]; p < 0.001) and need for extracorporeal membrane oxygenation support (odds ratio, 1.07 [1.02-1.13]; p = 0.01), but not for the development of bronchopulmonary dysplasia (odds ratio, 1.04 [0.99-1.09]; p = 0.14).'] Does score for Neonatal Acute Physiology-II predict Outcome in Congenital Diaphragmatic Hernia Patients?