Three cases of traumatic diaphragmatic hernia were repaired in this department from June 1967 to Nov.1968. The first case, a 14 year old girl, was diagnosed as diaphragmatic hernia during the operation of the diffuse peritonitis from jejunaI perforation 3 days after the traffic accident at local clinic and she was transfered to this hospital after the closure of the perforated jejunum. Herniated stomach, transverse colon, spleen and left lobe of the liver were repositioned and the diaphragmatic rupture at the posterolateral portion of the left diaphragm was repaired with two layer sutures by transthoracic approach. The second case. a 26 year old man. was diagnosed immediately after the traffic accident at local clinic and transfered to this hospital 24 hours later. Herniated and distended stomach, transverse colon and jejunum were repositioned and the large diaphragmatic rupture, about 9 cm in length, from the posterolateral portion to the base of the pericardium was directly repaired with two layer sutures. The third case, a 26 year old man, who had a history of stab wound at left lower lateral chest two years ago,was admitted with the sudden onset of abdominal pain and vomiting. The diaphragmatic hernia was confirmed with barium enema. The herniated stomach and transverse colon through the defect, about 3.5 cm in diameter, at anterolateral portion of the left diaphragm, were repositioned and the defect was repaired with two layer sutures. All of the cases recovered uneventfully.[KTCS 1969;1:59-64]