The concurrent diagnosis of breast cancer and pregnancy remains a challenging clinical situation. Ethical concerns regarding maternal and fetal well-being and potential risks and harms of treatment influence the clinical decision process. Ethical considerations of treatment initiation have emphasized the role of autonomy for the patient and the concept of beneficence and non-maleficence for patient and fetus. Limited prospective data are available to assist the physician and patient in making an informed decision. Recent data on diagnosis, evaluation, and management of pregnant patients with breast cancer have informed the development of international recommendations and guidelines for management of breast cancer during pregnancy. This article reviews the epidemiology, clinical presentation, diagnosis, therapy, and outcomes of breast cancer occurring concomitantly with pregnancy.