Full dose preoperative external irradiation was performed in cases of stage III cancer of the cervix (36 cases), and the effects were studied. The effects of preoperative irradiation on the operation, such as the time required for operation and the bleeding volume tended to be shorter and decreased, compared to stage III cases with postoperative irradiation (23 cases), and showed rather little difference when compared to cases of stage II with postoperative irradiation (85 cases). The postoperative effects, such as days required for the beginning of spontaneous urination, decrease in residual urine to less than 50 ml, and duration of fever (over 38 degrees C), did not differ from cases of stage III with postoperative irradiation, but there was a tendency to prolongation compared to cases of stage II. Histopathological examination of the specimen resected after the operation revealed that cancer parenchyma in the primary focus was influenced by irradiation in nearly 90% of cases, cancer cells showing degeneration and destruction with markedly decreased proliferative potentiality. Cases showing cancer infiltration into the vaginal stump and tip of the cardinal ligament were 8.3%, which was significantly lower than in stage III cases with postoperative irradiation. The frequency of metastasis to intrapelvic lymph node was 30.6%, significantly lower than 56.5% in stage III cases with postoperative irradiation, and lower than 36.5% in stage II cases. As to the postoperative complications raising clinical problems, disturbance of the urinary tract was noted in 52.8% and that of the rectum in 47.2%, but these complications became fatal in none.(ABSTRACT TRUNCATED AT 250 WORDS)