"Acquired" congenital diaphragmatic hernia (ACDH), has been defined as delayed or late appearance of a congenital diaphragmatic hernia after a documented time periol of postnatal life with no evidence of herniation. Three new cases are presented. This diagnosis has been characterized on the basis of a review of these cases and 14 additional patients from the literature. A classification based upon timing of herniation and state of pulmonary development is presented.