Purpose: To report mature results of a randomized trial that compared extended-field radiotherapy (EFRT) versus pelvic radiotherapy with concomitant fluorouracil and cisplatin (CTRT) in women with locoregionally advanced carcinomas of the uterine cervix. Patients and Methods: Four hundred three women with cervical cancer were randomly assigned to receive either EFRT or CTRT. Patients were eligible if they had stage IIB to IVA disease, stage IB to IIA disease with a tumor diameter ≥ 5 cm, or positive pelvic lymph nodes. Patients were stratified by stage and by method of lymph node evaluation. Results: The median follow-up time for 228 surviving patients was 6.6 years. The overall survival rate for patients treated with CTRT was significantly greater than that for patients treated with EFRT (67% v 41% at 8 years; P < .0001). There was an overall reduction in the risk of disease recurrence of 51% (95% CI, 36% to 66%) for patients who received CTRT. Patients with stage IB to IIB disease who received CTRT had better overall and disease-free survival than those treated with EFRT (P < .0001); 116 patients with stage III to IVA disease had better disease-free survival (P = .05) and a trend toward better overall survival (P = .07) if they were randomly assigned to CTRT. The rate of serious late complications of treatment was similar for the two treatment arms. Conclusion: Mature analysis confirms that the addition of fluorouracil and cisplatin to radiotherapy significantly improved the survival rate of women with locally advanced cervical cancer without increasing the rate of late treatment-related side effects.