From 1970-1985, 303 women with genitourinary fistulas were seen at the Mayo Clinic. The fistula formed after treatment for benign conditions in 74% of the patients and malignant conditions in 14%; in 12%, we were unable to establish the nature of the condition. Gynecologic surgery was responsible for 82% of the fistulas, obstetric procedures for 8%, various. forms, of irradiation for 6%, and trauma or fulguration for 4%. In the nonirradiated patient, the ideal time for operative repair was eight, to 12 weeks after fistula formation or failed repair. With ureterovaginal fistulas, the patient's general condition and the degree of obstruction of the ureter influenced the time and method of repair. We used a vaginal approach for urethral fistulas and an abdominal one for ureteral repairs. Because of difficulty with adequate exposure and the proximity of the ureter, an abdominal approach was used in 20% of the patients with vesicovaginal fistulas; the remaining 80% were approached vaginally, regardless of size, number, or history of previous repairs. Ninety-two percent of the urethrovaginal fistulas were corrected on the first attempt; the four failures were managed successfully at the second attempt. Ninety-eight percent of the vesicovaginal fistulas were corrected on the first attempt when approached vaginally, and all were managed successfully when approached abdominally, regardless of the number, size, or previous operative attempts.