The ten-year survival of patients at the Cleveland Clinic treated by operations less than radical mastectomy was 45% compared with 43% in identically staged patients of the "National Cancer Registry" treated predominantly by radical mastectomy. The five and ten-year survival rates of patients treated by simple operations was higher than that of a similar group of patients treated by radical operations, but at 15 years there was no difference. The late deaths from cancer in the patients treated conservatively occurred in patients with favorably staged cancers who never had local recurrences and most of whom had no involvement of nodes. The incidence of local recurrence was no higher after simple operations than after the radical procedure. The ten-year incidences of local recurrence and of death from cancer were the same after partial mastectomy as after total mastectomy. It is pointed out that differences in staging the cancers and in reporting the survival rates invalidate comparisons of results from different institutions. The figures presented suggest that conservative operations and radical operations give the same survival rates at ten and at 15 years.