Calcinosis cutis is a rare cause of non-healing leg ulceration. There are many factors that can delay the healing of venous leg ulceration and the deposition of calcium in the skin known as calcinosis cutis is one of these factors. There are five distinct forms: dystrophic calcification, metastatic calcification, idiopathic calcification, iatrogenic calcification and calciphylaxis. Warfarin skin necrosis has common clinical features with calciphylaxis and is therefore included in this article, which describes the types of calcinosis cutis, their clinical presentations and limited treatment options. The aim is to highlight these unusual causes and to assist healthcare professionals when faced with a non-healing ulcer.