Seven patients who had breast reduction surgery and whose preoperative physical examinations were unremarkable were found to have breast carcinoma. In the five in whom mastectomy was performed, most closures were difficult, and in one patient bilateral mastectomy was complicated by wound dehiscence. In only one of these seven was it possible to obtain information regarding the hormonal binding status of the tumor cells. These and other sequelae would not have occurred had the tumors been diagnosed before operation. Because physical examination alone is not sufficiently sensitive for the diagnosis of breast cancer, we suggest that mammography be included in the evaluation of patients consulting surgeons for breast reduction.