Forty-six patients initially treated for carcinoma of the breast by tumor excision and radiation therapy who had local and regional recurrence with no evidence of distant disease and who underwent salvage mastectomy at Memorial Sloan-Kettering Cancer Center between 1970 and 1990 were reviewed retrospectively. These patients represent a recent series of patients treated with breast-conserving surgery, radiation therapy and subsequent salvage mastectomy with a median follow-up period of five years (range of one to 20 years). The mean age at initial diagnosis was 52 years (range of 31 to 75 years). All patients had excision of the primary tumor; 27 underwent local excision with axillary dissection. The median radiation therapy dose to the breast was 48 Gy. The distribution of stage of disease at the time of breast conserving treatment was stage 0 in seven patients, stage I in 13 patients, stage II in 14 and stage III in one patient. Twenty-seven patients received conservation treatment at other institutions and were referred to our institution for salvage operation. Local and regional relapse occurred at a median of 28 months (range of five months to seven years) after initial treatment. Relapses occurred only in the breast in 35 patients, in the axilla in one patient and in both sites in ten patients. Salvage operation consisted of total mastectomy in 50 per cent, modified radical mastectomy in 33 per cent and radical mastectomy in 17 per cent. Follow-up evaluation after salvage mastectomy (median 28 months, range of one month to 18 years) yielded an actuarial proportion free of disease at five years of 55 per cent (+/- 11 per cent) and an over-all five year survival rate of 76 per cent (+/- 10 per cent). The median time to relapse was 97 months (+/- eight months) and the median survival time was 103 months (+/- seven months). The local recurrence rate after salvage mastectomy was 15 per cent. These data suggest that salvage mastectomy provides local control of recurrent carcinoma of the breast and relapse-free survival time may be improved by postsalvage systemic therapy.