Secretory breast carcinoma is a very rare tumor of the breast and has distinctive pathological characteristics such as (1) the presence of large amounts of intracellular and extracellular secretion and (2) granular eosinophilic cytoplasma of the cells. It usually occurs in children or adolescents and is known to have a better prognosis than the usual ductal carcinoma. The preoperative aspiration cytology is also distinctive and it could permit planning the optimal surgical therapy such as breast conservation surgery for young patients. We report a case of secretory breast carcinoma in a 35 year-old female and her preoperative aspiration cytology in Liu's stain. To our knowledge, Secretory breast carcinoma has not been reported previously in Taiwan.