Enterovesical fistula is a relatively uncommon complication of colorectal and pelvic malignancies, diverticulitis, inflammatory bowel disease, radiotherapy, and trauma in Asian countries. A case of vesico-ileosigmoidal fistula and a literature review of this disease in Japan are presented. A 70-yr-old male was referred with complaints of urinary pain and pneumaturia. On admission, urinary tract infection and pneumaturia were presented. A barium enema demonstrated multiple diverticulum in his sigmoid colon and the passage of contrast medium into the bladder and ileum. Under the diagnosis of vesico-ileosigmoidal fistula due to suspected diverticulitis of the sigmoid colon, sigmoidectomy and partial resection of the ileum with partial cystectomy were performed. The histopathology revealed diverticulosis of the sigmoid colon with diverticulitis and development of a vesico-ileosigmoidal fistula. No malignant findings were observed. Until the year 2000, a total of 173 cases of vesico-sigmoidal fistula caused by diverticulitis had been reported in Japan. Pneumaturia and fecaluria are the most common types, presenting symptoms in 63% of the cases. Computed tomography, with a sensitivity of 40% to 100%, is the most commonly used diagnostic study. For patients with vesico-sigmoidal fistula, resection of the diseased sigmoid colon and partial cystectomy with primary anastomosis are the safest and most acceptable procedures, leading to the best results.