From 1968 to 1977, 21 patients were observed who had fistulas between the bowel and the urinary tract. Except in five patients, fistulas were located vesicointestinally. The main etiologic factors were inflammatory lesions of the bowel, especially diverticulitis and appendicitis. All patients had symptoms relating to the urinary tract, mainly recurrent urinary infection with dysuria. On the average, nine months passed until the fistula was diagnosed. Urethrocystoscopy proved to be the most valuable aid in diagnosing intestinovesical fistulas, the fistulous opening was thus seen in 11 patients. Thirteen patients were treated by operation and eight by conservative treatment only. In the conservatively treated group, two fistulas healed spontaneously. Fistulas based on diverticulitis from the sigma were treated using a multiple stage procedure. No complications were observed.