Patients with chronic kidney disease (CKD) or end-stage renal disease (ESRD) are known to develop metastatic soft-tissue calcification, secondary to hyperparathyroidism, in tissues including the breast. Such calcifications in women could pose a problem for interpretation of mammograms, since they are thought to mimic malignant lesions and interfere with differentiation of benign from malignant disease. Investigation of this issue is important to provide high-quality, accurate breast care to women with CKD or ESRD, but little evidence is so far available. In a systematic review of the literature on the types and patterns of breast calcifications, we found only three studies that examined metastatic soft-tissue calcifications of the breast. The studies did, however, confirm that women with CKD or ESRD have a higher frequency of breast calcification than women with normal kidney function. The two older studies reported that these breast calcifications are not associated with malignancy, but the later study reported a raised rate of suspicious breast calcification among women with ESRD receiving hemodialysis, leading to an increased biopsy referral rate. In this Review we discuss the strengths and limitations of the available data and whether mammography is recommended in women with CKD or ESRD.