The early follow-up of patients treated by simple mastectomy alone or simple mastectomy combined with radical radiotherapy is presented. Both groups were well matched for age, menopausal status, duration of symptoms, size of tumour, and lymph-node involvement. There was no significant difference in survival of patients in the two groups at three years, but local recurrence was significantly more frequent (28%) in the mastectomy-alone patients. Early survival was not adversely affected by radiotherapy.