Delayed presentation of a traumatic diaphragmatic hernia is an infrequent condition with a high mortality and morbidity rate. This case describes a 26-year-old man presenting with a 2-day history of cramping abdominal pain, dyspnea, nausea, and vomiting. The patient reported a penetrating thoracic injury one year prior to the development of clinical signs. Computed tomography revealed the presence of empyema or parapneumonic effusion of the left hemithorax. Based on the clinical history and physical findings, a diaphragmatic hernia was considered and an emergency laparotomy with segmental resection of strangulated jejunum and reduction of remaining bowel was performed. A 1.5 cm tendinous defect was identified and repaired. The patient recovered and was discharged uneventfully.Conclusion: the early recognition of a delayed diaphragmatic hernia contributed to the uneventful recovery of this critically ill patient.