A 47-year-old patient presented at our emergency department with acute epigastric pain. A thoracic X-ray showed a partially intrathoracic stomach as well as bowel left sided. A following computed tomography scan diagnosed a diaphragmatic hernia. In the patient’s history, 20 years ago a serious car accident was reported as the presumable traumatic origin. Intraoperatively, the diaphragmatic hernia was repaired with a direct suture and mesh augmentation. The rest of the abdomen was clear. In a thoracic X-ray following chest tube removal, herniated small bowel appeared intrathoracally on the right. Relaparotomy showed an extensive diaphragmatic hernia with parts of the liver, small bowel and colon in the right thoracic cavity. Only a partial direct repair was possible, an inlay mesh repair was performed. The further recovery was uneventful. Bilateral delayed traumatic diaphragmatic hernias are extremely rare, but with a suggestive trauma history thorough intraoperative exploration of the contralateral side should be evaluated.