Breast cancer in men is a rare cancer manifestation, accounting for less then 1% of all breast cancers in both genders. The incidence in Germany during the last years has been approximately 1.0 per year/100,000. In the US, only 0.2% of all malignancies in men. Predisposing risk factors seem to include radiation exposure, hereditary factors, estrogen administration, and diseases associated with hyperestrogenism, such as cirrhosis of the liver or genetic syndromes (i.e. Klinefelter disease). The incidence of male breast cancer is increased in families with a number of first degree relatives affected with breast or prostate cancer. An increased risk of male breast cancer has been reported in families with a mutation of the breast cancer susceptibility gene BRCA-2. For a period of decades, prognosis of breast cancer in males was thought to be worse than that of female patients. Data and cases being published demonstrate that prognosis and strategies of treatment in male breast cancer do not differ from those in females. The cases presented clearly demonstrate that diagnostic work-up, staging procedures and treatment options for primary treatment and advanced stages are identical compared to the recommendation for female breast cancer.