Ileovesical fistula is a very rare clinical entity, the most frequent cause of which is Crohn's disease. Furthermore, it is an exceptionally rare complication of malignancies. We experienced one case of ileovesical fistula which had been caused by hepatocellular carcinoma (HCC) arising from the noncirrhotic liver. A 27-year-old man was diagnosed with HCC in a noncirrhotic liver. Despite treatment with transarterial chemoembolization (TACE), the disease status became more aggravated. The patient complained of dysuria, fecaluria, and intermittent lower abdominal pain. Pelvic CT scan showed a soft tissue mass of 6 cm abutting on the distal ileum which was downwardly displaced. Barium study of the small bowel showed a fistula between the small bowel loop and the urinary bladder. Upon operation, adhesion and fistula were found between the ileum and the urinary bladder. The microscopic findings of the surgical specimen were compatible with metastatic HCC. We confirmed that ileovesical fistula had been caused by metastatic HCC.