Introduction Traumatic diaphragmatic hernia frequently is not diagnosed upon the first admission, and late presentation associated to complications of herniated organs is common.Even though, these cases are rare. Herein we discuss a patient with late presentation of traumatic diaphragmatic hernia with gastric necrosis and his surgical treatment. Case description A male patient, 23 years-old, with a previous penetrating wound over the left hemithorax 18 months before admission, presents to the Emergency Unit of our Institution complaining of thoracic pain associated to vomit. A thoracic computed tomography showed a left diaphragmatic hernia with intrathoracic stomach and pleural effusion. Surgical findings were a hernia ring of 3 cm of diameter with almost all stomach herniated into the left hemithorax. Around 90% of the herniated stomach was necrotic as well as the associated greater omentum. A total Gastrectomy was performed. The diaphragmatic defect was repaired with separated polypropylene stitches. Postoperative evolution was uneventful. The histology of the surgical specimen showed hemorrhagic infarct of the stomach wall and mucosal necrosis. Discussion Late presentation with necrosis of the herniated organs in patients with posttraumatic diaphragmatic hernia represents the habitual presentation in these cases. The diagnosis is facilitated with the use of computed tomography and early surgical intervention has good prognosis.