Breast cancer is the most common malignancy among reproductive-aged women, and an increasing number of women are breastfeeding at the time of screening initiation. The literature was reviewed to identify evidence-based guidelines for breast cancer screening during lactation. Health care providers should consider routine age-related or high-risk screening; they should also discuss alternate surveillance strategies, including deferment until cessation of breastfeeding. Shared decision-making and individualized patient care should involve consideration of the limitations of current evidence. Lactation-related radiographic changes may make examination interpretation more challenging; preprocedure milk expression and use of particular supplemental imaging modalities can improve examination sensitivity. Despite these strategies, breastfeeding women may have higher rates of false-positive findings and therefore undergo more biopsies. However, given the increased risk of biologically aggressive breast cancers in postpartum women, these risks may be outweighed by the benefits of routine breast cancer screening for breastfeeding women.