Missing the diaphragmatic injury on first admission is often associated with late complications. A 38 year-old male patient is presented here as a case of missed diaphragmatic injury due to gunshot injury resulted with fecal peritonitis. Celiotomy revealed a distended appendix perforation due to herniated left colon obstruction through the left pleural cavity. Left colon and stomach were reduced to peritoneal cavity and diaphragm was repaired with interrupted polypropylene sutures. After being sure about the viability of the colon and stomach, appendectomy with cecal exteriorization was performed. Postoperative period was uneventful. The patient was discharged on the 10th postoperative day. A thorough inspection of the diaphragm is essential in thoraco-abdominal trauma. Repair of the diaphragmatic defects should invariably carried out to avoid life-threatening complications
