Most described male breast lesions, such as gynecomastia, are benign. The overall incidence of male breast cancer is less than 3%. Like women, common presentations of male breast diseases are palpable lumps or tenderness. Physical examination, mammography and ultrasound are generally used for work-up of breast diseases in both women and men. However, men do not undergo screening mammograms; all male patients are examined in symptomatic cases only. Therefore, all male breast examinations are diagnostic, whereas the majority of the examinations for women are for screening purpose. The differentiation between benign and malignant breast lesions is important, especially for men, because the reported prognosis of male breast cancer is poor due to delayed diagnosis. In this article, we review the spectrum of male breast diseases, from benign to malignant, and illustrate their ultrasonographic and mammographic imaging features.