Background Management of neonatal congenital diaphragmatic hernia (CDH) with permissive hypercapnia (PHC) and postductal hypoxemia (PHO) was first described by Wung et al in 1985. In 1997, Wilson et al reported that PHC, unlike HFOV or ECMO, increased survival in newborns with CDH. This was followed by other reports of success using permissive strategies in nenates with high-risk CDH. Although the strength of the evidence is grade B, no other rescue strategy has been shown to be beneficial in CDH. Objective To describe trends in management of neonatal CDH and to determine if permissive strategies are associated with improved outcome in this population. Design/Methods 1,210 cases from 53 centers entered into the CDH Study Group Registry as of 10/1/05 were analyzed. Variables included sex, race, gestation, birth weight, Apgar scores, defect size and side, worst PaCO2, best postductal PaO2, and ventilatory management style. End points were survival, ECMO use, and chronic lung disease (CLD, O2 at 30 days). Chi-square was used for categorical and ANOVA for continuous variables. Results After 1998, the use of PHC and/or PHO in CDH infants rose with a committant fall in the use of hyperventilation/hyperoxia. Mortality did not change, but infants entered into the Registry after 1998 were more severely affected based on blood gas values and defect size. Fifty-two percent of infants reported by participating institutions had been managed using PHC and/or PHO. Eighty-one percent of participating centers reported use of one or both permissive strategies. In 60% of centers, this was the predominant management style. Demographic and clinical characteristics of CDH infants treated with and without PHC and/or PHO were similar. Use of PHC and/or PHO decreased mortality (28 vs 35%, p = .03) and ECMO use (29 vs 36%, p Conclusions Use of PHC and/or PHO appears to be the new standard of care for CDH infants. Its use increases survival and decreases ECMO use. The improvement in survival is paralleled by an increase in CLD, suggesting that the strategy is most effective in neonates with severe CDH.