Abstract Eventration of the diaphragm was noted in 69 children over a 20-yr period. The origin of the eventration was congenital in 48, acquired in 21. Nonoperative treatment was successful in most patients with symptomatic congenital eventration. Fourteen children with congenital eventration had operative plication. Three patients with gastric volvulus and total eventration of the left diaphragm were among those operated upon. There was one mortality in the medically treated group and two deaths in those treated surgically. All symptomatic patients with acquired eventration were managed non-operatively. The elevated, paralyzed diaphragm resulted from either birth or intraoperative trauma in all cases. There was one death among the 21 children with acquired eventration.