Diaphragmatic injury accompanied by herniation through the thoracic cavity is a well documented complication of penetrating or blunt abdominal trauma. It occurs in 3% of abdominal lesions, with strong prevalence for blunt trauma. In the acute setting the diagnosis may be difficult because of the lack of peculiar clinical signs or the wrong interpretation of radiological findings. For this reason, medical history taking should be very accurate, in order to underline the correlation between a past traumatic event and the present symptoms. If the defect is not promptly recognized, the patient has a considerable increase in morbidity and mortality risk. In our case the presentation of the diaphragmatic injury was delayed and the correct diagnosis was not suspected initially. We report the case of a 28 years old man presenting to our department for sudden abdominal pain associated with bowel obstruction. Patient underwent an urgent laparotomy that revealed a postero-lateral diaphragmatic hernia with incarcerated colon and omentum, which appeared ischemic and were therefore resected, with successive closure of the diaphragmatic breach. During medical history taking the patient signaled a penetrating trauma occurred eleven years before symptoms presentation.