Five cases of traumatic diaphragmatic hernia were repaired in the Department of Thoracic Surgery, Seoul National University Hospital, during the period from 1967 to 1974. The first case, a 14-year aid girl, was diagnosed as diaphragmatic hernia during laparotomy because of jejunal perforation 3 days after traffic accident. Herniated stomach, transverse colon, spleen and left lobe of the liver were repositioned and the diaphragmatic rupture on left posterolateral portion was repaired with two layers of nonabsorbable sutures by transthoracic approach. The second case, a 26-year old man,was diagnosed immediately after traffic accident at a local clinic and transferred to this hospital 24 hours later. Herniated stomach, transverse colon and jejunum were repositioned amd diaphragmatic rupture,about 9 cm in length,from the posterolat.edge to the base of pericardium was sutured in two layers. The third case, a 26-year old man who had stab wound on the left lower lateral chest two years ago,was admitted with sudden abdominal pain and vomiting. Upper gastrointestinal series with barium meal revealed diaphragmatic hernia. The herniated stomach and transverse colon through the defect,about 3.5cm in diameter, at anterolateral portion on the left side,were repositioned and repaired with two layers of nonabsorbable sutures. The forth case, a 26-year old man, sustained blunt trauma to the chest by a roller and was transferred to the emergency room complaining of dyspnea 40 minutes after the accident. The diaphragmatic rupture extended from left midaxillary line to contralateral anterior axillary line,about 20cm long, at anterior portion of diaphragm, which was repaired with two layers, of nonabsorbable sutures. The fifth case, a 4-year old girl, had two separate diaphragmatic ruptures on both sides, which were caused by traffic accident. Immediate upper gastrointestinal series after injury showed herniated stomach, colon and spleen into left Chest cavity. Another small rupture with anterior edge of right lobe of the liver in chest cavity was noted. These were repaired with non-absorbable sutures via thoracotomy.[KTCS 1974;2:163-168]