From 1949 through 1976, 97 men have been treated at Memorial Hospital for primary operable breast cancer. Seven per cent had intraductal carcinoma. Of the patients with invasive carcinoma 30% were pathologic stage I, 54% stage II, and 16% stage III. Fourty-six per cent had pathologically negative axillary lymph nodes. The most common type of tumor was infiltrating duct carcinoma. Fourty per cent of the patients had microscopic gynecomastia. None of the eight patients with intraductal or intracystic carcinoma died of cancer. Survival of the entire group of men with invasive carcinoma was 40% after ten years. The ten year survival for men with negative nodes was 79%, for men with positive nodes 11%. Comparison with a series of 304 women with breast cancer operated on at Memorial Hospital in 1960 revealed no difference with regard to incidence of positive axillary lymph nodes or stage of disease. There was, however, a significantly lower survival rate for men. This poorer prognosis was limited to those men with pathologically positive axillary nodes.