During twenty one years from 1934 to 1954 inclusive, 1,974 cases of cancer of the uterine cervix were treated by radiation therapy in the gynecological department of Okayama University. The urinary and fecal fistulae were found in 13 cases (0.7%) during the I. series and in 30 cases (1.5%) after leaving the hospital. There were; urinary fistulae 1.2% (22 cases of vesico-vaginal, 1 case of urethro-vaginal), fecal fistulae 0.9% (18 cases of rectovaginal), and urino-fecal fistulae 0.1% (2 cases of recto-vesico-vaginal). Thirteen cases of them showed evidently signs of fistulae during admission, and their subjective symptoms were as follows: in the urinary fistula, 7 cases out of 11 complained of vesico-urethral irritation symptoms; in the fecal fistula, one case out of 2 complained of mucous stool and of discomfort in the anal region. There were observed no relations to their age groups (less than 49 and over 50), the deliveries (less than 4 times including none, and over 5 times), and the state of presence of the cancerous infiltration in the vaginal wall on observation in the first examination. There was a tendency to produce urinary and fecal fistulae more frequently in the ulcerative or crateriform cancers than in the cauli flower-like or erosive, and in the progressed cancer patients. The curability was very low in these fistulae occurred during the radiological treatment. Most of them died of cancer; about 1/2 of them were within one year, about 1/4 within 2 to 5 years and the rest 1/4 belonged to the cases of 5-year survivals.