INTRODUCTION: Gallstone ileus (GSI) is a rare complication of cholelithiasis (gallbladderstone), which may lead to obstruction of the small intestine. Particularly, computerized tomographic (CT) imaging method and special findings in these images help diagnosing of gallstone ileus. Treatment of this disease is surgery, surgery involves cholecystectomy + fistula repair + enterolitotomy, but it is controversial to perform cholecystectomy with enterolitotomy and fistula repair in the same session.PRESENTATION OF CASE: A 75-year-old male patient consulted to the emergency department with the complaints of nausea and vomiting. In the examinations of the patient, bilienteric fistula and gallstones that impacted in the jejunum leading to obstruction were observed in abdominal CT images of the patient who has ileus. The patient was evaluated as gallstone ileus. In addition, on tomographic images significant Forchet sign and Rigler's triad images were viewed which were pathognomonic for gallstone ileus and did not have images as clear as in our case in the literature search. Laparotomy was performed on the patient due to the fact that he was elderly and the duration of anesthesia was wanted to be kept short and stone was extracted by enterolitotomy. Cholecystectomy and fistula repair were left for another session because of gallbladder and surrounding tissues were edematous. The patient was discharged with full recovery on the 6th post-operative day.DISCUSSION-CONCLUSION: As well as this disease is a rare cause of mechanical bowel obstruction, it is mostly seen in elderly patients. The most sensitive and specific imaging method in diagnosis is contrast enhanced abdominal computerized tomography. In the tomographic images, especially the Rigler's triad, Forchet sign and Petren sign are pathognomonic for gallstone ileus. (C) 2019 The Author(s). Published by Elsevier Ltd on behalf of US Publishing Group Ltd.