A retrospective analysis is reported on the results of irradiation alone in the treatment of 970 patients with histologically proven invasive carcinoma of the uterine cervix. The development of the radiation therapy techniques, survival, pelvic tumor control, and major sequelae of therapy are described in detail. The tumor-free 5-year survival rate was 100% in 29 patients with stage IA, 85% in 312 cases with stage IB, 70% in 98 patients with stage IIA, 68% in 276 patients with stage IIB, 45% in 237 stage III cases, and one survivor in 18 stage IV patients. No pelvic recurrences or distant metastases were observed in stage IA patients. In stage IB the overall incidence of pelvic recurrences was 7.3%, in stages IIA and IIB 14%, and in stage III 37%. Distant metastases were noted in 13% of the patients with stage IB, 22% of those with stages IIA and IIB, and 32% of patients with stage III tumors. Higher doses of irradiation delivered with intracavitary insertions and extenal beam were correlated with a lower incidence of pelvic recurrences in stages IIA, IIB, and III. However, doses to point A over 7000 cGy did not improve pelvic tumor control in stage IB. Grade 2 treatment sequelae were observed in about 10% of all patients and grade 3 complications in approximately 4% of the patients with stage I and 8% in those with more advanced tumors (IIA and beyond). The need is emphasized to carefully evaluate the dosimetric aspects of new techniques, including phantom studies before they are applied to patients. A close integration of external and intracavitary irradiation will result in better tumor control and fewer complications.