Calciphylaxis is vasculopathy characterized by ischemia and painful skin necrosis due to calcification and intimal fibroplasia of thrombosis of the panicular arterioles. It most frequently compromises patients with terminal chronic renal failure and has a high mortality rate. Biopsy of skin lesions is used as a diagnostic method. No specific laboratory findings have been recorded. Skin lesions usually begin in the extremities like a painful purplish mottling similar to "livedo reticularis". The natural evolution is to ulcers and bedsores. The first line of treatment involves the care of skin lesions and antibiotic therapy. Sodium thiosulfate is used as treatment due to its antioxidant activity and as a chelating. Two clinical cases are here reported.