An overview of mortality in the mature randomized trials comparing radical mastectomy without radiotherapy against simple mastectomy with radiotherapy has been conducted. These trials mark a transitional period between radical mastectomy and simple mastectomy as the generally preferred surgical treatment and as such are not strictly trials assessing the value of postoperative adjuvant radiotherapy. All known mature trials have been included and these four trials have entered a total of 3236 patients, in whom 1678 deaths have been recorded. Overall, no significant difference in survival was seen, but there was a nonsignificant trend for patients given radiotherapy to do worse after 15 years of follow-up.