A 27-year-old man presented with a 5 day history of abdominal pain and distension, with associated constipation and vomiting. He had presented 8 years earlier following a traumatic injury to the left side of the chest, and no diaphragmatic injury was reported at that time. On this admission, a computed tomography scan showed herniation of the splenic flexure of the colon into the left hemithorax. Subsequently, he had an emergency laparotomy for resection, with formation of a loop ileostomy. The various imaging techniques all have advantages and disadvantages when diagnosing a traumatic diaphragmatic hernia. It is the clinician’s role to maintain a high index of suspicion when a patient initially presents with trauma where a traumatic diaphragmatic hernia may be a possibility.