Calciphylaxis is a rare disorder associated with calcification of small- and medium-sized blood vessels, and progressive skin necrosis usually seen in the setting of end-stage renal disease (ESRD) and secondary hyperparathyroidism. It has also been observed in primary hyperparathyroidism, hypercalcemia of malignancy (extensive bony metastasis of breast cancer), and an isolated case reported with end-stage liver disease. We report an unusual case of calciphylaxis associated with metastatic breast carcinoma in the absence of renal or parathyroid disease. Calciphylaxis has generally been associated with end-stage renal disease and hyperparathyroidism. One previous case report described calciphylaxis occurring in a patient with metastatic adenocarcinoma of the breast and hypercalcemia. Our case represents the second reported case of calciphylaxis associated with osteolytic, metastatic breast cancer. Although ESRD with secondary hyperparathyroidism is the most common presentation of calciphylaxis, this case demonstrates that other conditions that alter normal calcium metabolism must be considered in the differential diagnosis.