The results of treatment of uterine cervix cancer by radiotherapy alone in 259 patients in the period January 1973 to December 1984 are reported. They are analyzed according to patients age, stage, tumor volume, extent of parametrial infiltration, hydronephrosis and nodal status. It is shown that age, tumor volume, extent of parametrial invasion and nodal metastases are the main prognostic factors. Analysis of pelvic failures shows that external radiotherapy followed by curietherapy seems to be the best method for patients with T2b and T3b tumors of small volume (less than 60 mm in diameter), particularly when parametrial infiltration is limited. Patients with T2b tumors of large volume (barrel shaped) seem to need a more aggressive approach, and a higher number of complications are therefore expected. Patients with T3b and massive parametrial infiltration, with T4 and nodal metastases need new and different approaches, possibly including adjuvant chemotherapy.