We report a rare case of a 77-year-old man with a known left inguinal hernia presenting with groin pain following a blunt trauma of the left leg. Diagnosis of small bowel perforation away from the hernia was obtained only in surgery. Difficulty in preoperative diagnosis, rarity of histologic pattern, and surgical challenges make this case very interesting for surgeons and radiologists. Our conclusion upon dealing with the situation is that the diagnosis of small bowel perforation following blunt injury to a non-abdominal trauma is rare and difficult. The association between inguinal hernia and non-abdominal trauma may result in small bowel injuries that normally do not appear. Therefore, clinicians should be cautious in treating non-abdominal trauma patients with inguinal hernias.