From 1966 to 1979, 235 patients with operable breast cancer were treated by tumor excision and radiotherapy. The actuarial survival at 10 years was 94.8% for stage I and 58% for stage II tumors. Local recurrent cancer was seen in 23/235 patients and was related to T stage, N stage, width of surgical excision, radiation dose to the tumor bed and anatomopathological differentiation. Recurrences were seen in 1/7 of T0, 3/57 (5.2%) of T1, 11/102 (10.8%) of T2 and 2/6 of T3 tumors. Local control in the breast decreased significantly in N1b cases (p = 0.005) or when 3 or more axillary lymph nodes were positive (p = 0.0074). Local control after segmentectomy or tumorectomy was identical. However, a poorer local control was found in 20 cases treated with subtotal resection (p less than 0.05). A clear dose-local control relationship was found in this material, with a 100% local control in all T0, T1 tumors which received more than 1800 ret and all T2 tumors which received more than 2000 ret. As 19 of 23 breast recurrences were seen at the primary site in the breast we believe that booster doses should be given in order to maximise local control.