A retrospective study of 175 patients with T1-T3N0M0 carcinoma of the bronchus treated by radical radiotherapy at the Christie Hospital and Holt Radium Institute, Manchester between 1971 and 1980, is presented. Survival corrected for intercurrent death was 60.3% at 1 year and 19.6% at 5 years. Excluding T3 tumours which were all fatal by 5 years, corrected survival was 64.6% at 1 year and 26.0% at 5 years. A definition of the type of tumour suitable for radical radiotherapy is given.