Paget's disease of the breast is a rare disorder of the nipple-areola complex that is often associated with an underlying in situ or invasive carcinoma. A change in sensation of the nipple-areola, such as itching and burning, is a common presenting symptom. Objectively, eczematoid changes of the nipple-areola complex are common. The later stages of Paget's disease of the breast are characterized by ulceration and destruction of the nipple-areola complex. Eczematoid changes of the nipple-areola complex and persisting soreness or itching, without obvious reason, is a suspicious symptom for Paget's disease of the breast and calls for thorough evaluation, including mammography. Exfoliative cytology with demonstration of Paget's cells may be useful, but a negative finding does not exclude Paget's disease of the breast. Surgical biopsy is the diagnostic standard and therefore the diagnosis should always be confirmed by open (surgical) biopsy. The histogenesis of Paget's disease of the breast continues to be debated. The epidermotropic theory holds that Paget's cells are ductal carcinoma cells that have migrated from the underlying breast parenchyma to the nipple epidermis. According to the in situ transformation theory, the Paget's cells arise as malignant cells in the nipple epidermis independent from any other pathologic process within the breast parenchyma. This theory has been proposed to explain those cases in which there is no underlying mammary carcinoma or when there is a carcinoma remote from the nipple-areola complex. Each of these theories is plausible; however, treatment approaches differ markedly depending on the theory of histogenesis. Mastectomy has been considered the standard of care in the management of patients with Paget's disease of the breast. Nowadays, however, some patients with Paget's disease of the breast are candidates for breast-conserving therapy. Patients must be selected carefully on an individual basis. Until there is a better understanding of the relationship of Paget's disease of the breast to the underlying cancer the surgeon should understand the natural history and behaviour of this lesion and be aware of both the risks of under- and over-treating patients with Paget's disease of the breast.