Twenty two cases of stage I breast cancer underwent modified radical mastectomy and 77 cases of stage II~IV standard radical mastectomy at our surgical department from January, 1978 to December, 1981. All exept one patient on whom modified radical mastectomy was performed, have been healthy without showing any recurrence or metastasis. This one case was a 90-year-old lady who died of old age 35 months after Surgery. Of 73 patients treated by standard radical mastectomy, 6 died of recurrence, and metastatic lesions have been observed in 4 patients. From our experiences, we would like to emphasise that modified radical mastectomy for early stage breast cancer is excellent method because of its convenience and efficacy.