Ileovesical fistula is a rare condition in children. A case of 13 year-old female with ileovesical fistula caused by an ingested foreign material is presented. She had dysuria and lower abdominal pain for one month. There was no history of medico-surgical illness such as Crohn's disease or diverticulitis. Preoperative imaging study showed a movable calcified object in the pelvic cavity and air bubbles in the bladder. At laparotomy a bezoar-like mass was found at the antimesenteric border of the terminal ileum adherent to the dome of bladder. Segmental resection of the ileum and partial cystectomy were performed.