The survival of 209 patients with apparently localized carcinoma of the prostate treated by radical external beam radiotherapy is reported, noting the influence of age, stage of the disease at presentation, initial histology, previous surgery, and dose of radiotherapy given. From this it is seen that the development of a six-fraction regimen given over a period of three weeks leads to excellent results whether assessed as a local response or by survival curves and to the economical use of scarce resources, but, even more important, is less wearing for patients than conventional daily fractionation and with no major early or late morbidity recorded up to October 1986.