Background: Torsion of the appendix is a rare entity and divided into two categories: primary and secondary. The primary mode is due to an abnormality in either appendix anatomy or its meso or both and is more common in children. The secondary forms happen in adults which can be associated with appendiceal tumor, appendiceal mucocele, fecal impaction, volvulus of ovarian cyctadenoma. Adynamic small bowel obstruction or ileus is seen frequently with all forms of peritoneal inflammation. However, Anatomical small intestinal obstruction or gangrene due to torsioned appendix is a rare condition and few cases reported in the literature. Method: Here we have a 83- year-old man patient with small bowel obstruction and localized right lower quadrant peritonitis who undergo emergency laparotomy to eliminate small bowel obstruction and peritonitis. Preoperative abdominal radiography showed multiple dilated small bowel loops with empty colon. Results: During exploration necrosis of the terminal 40cm of the ileum due to a twisted and gangrenous appendix was discovered. Other parts were normal. Conclusion: it may be useful to recommend early midline exploratory laparotomy for patients with small bowel obstruction even in the presence symptoms of local appendicitis. This operation can be both diagnostic and therapeutic.