Between 1960 and 1966, 258 carcinomas of the breast with a follow up of 10 years or more formed a group which had been treated conservatively. Two conservative approaches were used, either lumpectomy followed by irradiation, or irradiation, alone, surgery being reserved for failures. At 10 years the survival rate of 51 p. 100 with no sign of recurrence is comparable with the results of radical or modified mastectomy. Among those living with no sign of recurrence 61 p. 100 had retained their breast almost always with a satisfactory aesthetic result. The place of lumpectomy followed by irradiation is reserved for single lumps of small volume and unaccompanied by axillary lymph node enlargement.