Gallstone ileus is a complication of cholelithiasis which is due to gallstone migration through a fistula between the gallbladder and the gastrointestinal tract followed by intraluminal impaction. This uncommon form of mechanical bowel obstruction occurs in <1% of patients with cholelithiasis. Gallstone ileus due to cholecystocolonic fistula is rare, and therefore appropriate surgical treatment is still a matter of debate. We describe a unusual case of gallstone ileus in a 74-year-old man with a history of cholelithiasis, admitted to our hospital with suspected largebowel obstruction. The diagnosis was made with abdominal computed tomography scan that showed a very large gallstone impacted in the sigmoid causing mechanical bowel obstruction. After endoscopic removal was attempted but proved unsuccessful, enterotomy was performed to remove the gallstone. At surgery a Meckel’s diverticulum was discovered incidentally and removed and trasversostomy was performed. The patient was discharged on postoperative day 10.