Three cases of calciphylaxis in patients with terminal renal insufficiency are discussed. The existence of metastatic calcifications, mainly vascular, in patients with chronic renal insufficiency is frequent. However calciphylaxis is a process which is rarely found in these patients. This entity is characterized by the obliteration of small vessels with ischemia and necrosis. The exceptionality of the disease, its difficult treatment and poor evolution make calciphylaxis a bad prognostic complication which should be considered in the differential diagnosis of cutaneous lesions in patients with chronic renal insufficiency.