Congenital diaphragmatic hernia is an important cause of respiratory distress in the newborn. Eventration, with which these conditions are easily confused, may also Produce severe respiratory distress in infancy or be an asymptomatic radiographic finding. Harrington`s classification of diaphragmatic hernias into two categories, traumatic and nontraumatic, is most widely accepted. Nontraumatic hernias are [1] the congenital types, composed of the posterolateral [Bochdalek], those through the esophageal hiatus, the parasternal [/Morgagni], and those through a defect left by partial absense posteriorly, and [2] the acquired types, composed of those through the esophagea/hiatus [sliding and paraesophageal] and those the sites mentioned above under the congenital hernias. During the period from 1970 up to October 1978, 21 cases of diaphragmatic hernia were treated in department of cardiovascular and thoracic surgery. 11 cases of Bochdalek hernias, 1 case of Morgagni hernia, 5 cases of diaphragmatic eventration and 3 cases of hiatal hernia [2 cases of paraesophageal and 1 cases of sliding type], were experienced. 3 cases of 20 died of respiratory insufficiency, 2 cases of mortality were combined with left lung hypoplasia with Bochdalek hernia.[KTCS 1978;4:433-440]