A 79-year-old man was admitted to our hospital for abdominal pain and distention. Ten years ago, he had been treated for ileus due to an enterolith at another hospital, where endoscopic lithotripsy ended in failure. He had occasionally suffered from abdominal pain during the past 10 years. After admission to our hospital, computed tomography revealed a stone in the terminal ileum. Small bowel enteroscopy showed an enterolith, however, endoscopic lithotripsy was unsuccessful. Although he was very old and had chronic obstructive pulmonary disease, operation with a mini-laparotomy 4 cm in length was performed. Bowel swelling by an enterolith and stenosis were observed 10 cm and 30 cm oral from the iliocecal valve, respectively. The enterolith was extirpated by an enterotomy of the stenotic portion. The stone was 40 mm in diameter, and had four layers. Chemical analysis of the stone revealed calcium oxalate, indicating a true enterolith. The postoperative course was uneventful and he left hospital on the 16th postoperative day. Ileus due to a true enterolith is rarely cured by conservative therapy, and has a risk of intestinal perforation, therefore, it should be treated as soon as it is diagnosed. Our case was safely treated by mini-laparotomy and stricture-plasty.