The phenomenon of calciphylaxis is rare, but potentially fatal. It has been recognised for a long time in patients with chronic renal failure with secondary hyperparathyroidism. Disturbed calcium and phosphate metabolism can result in painful necrosis of skin, subcutaneous tissue and acral gangrene. Appearance of the lesions is distinctive but the pathogenesis remains uncertain. The beneficial effects of parathyroidectomy are controversial. However, correction of hyperphosphataemia or occasionally hypercalcaemia is imperative. Fulminant sepsis as a consequence of secondary infection of necrotic and gangrenous tissue is a frequent cause of patient morbidity and mortality.