Breast carcinoma in men is rare and comprises approximately 1% of all breast cancer cases. In contrast to the increase in the detection rate of ductal carcinoma in situ (DCIS) in women resulting from the wide use of screening mammography programs, the rate of male DCIS is still small and represents approximately 5% of all male breast cancers. Considerable debate exists concerning the nature of this entity, including the clinical course, pathologic findings, treatment, and prognosis. In this review, the relevant literature dealing with male DCIS is summarized in an attempt to more precisely define the features of this disease.