The male breast is susceptible to many of the same pathologic processes as the female breast. Many of these conditions have mammographic, ultrasonographic (US), and magnetic resonance imaging findings that allow differentiation between clearly benign conditions and those that require biopsy. Gynecomastia is the most common abnormality of the male breast and has characteristic imaging features that usually allow differentiation from malignancy. Mammography is the initial imaging modality for a clinically suspicious mass. A palpable mass that is occult or incompletely imaged at mammography mandates targeted US. Suspicious or indeterminate masses require biopsy, which can usually be performed with US guidance. Approximately 0.7% of breast cancers occur in men. Men with breast cancer often present at a more advanced stage than do women owing to a delay in diagnosis. Benign breast neoplasms that may occur in men include angiolipoma, schwannoma, intraductal papilloma, and lipoma. Benign nonneoplastic entities that may occur in the male breast include intramammary lymph node, sebaceous cyst, diabetic mastopathy, hematoma, fat necrosis, subareolar abscess, breast augmentation, venous malformation, secondary syphilis, and nodular fasciitis. Familiarity with the salient features of the classic benign male breast conditions will allow accurate imaging interpretation and avoid unnecessary and often invasive treatment. © RSNA, 2013.