Gangrene is the macroscopic death of the tissues with superadded putrefaction. This chapter describes etiology, clinical features, clinical types, spread of gangrene and its treatment in general. Individual causes of gangrene and diseases affecting arterial system are described in detail with the help of clinical photographs, boxes, flow charts and case summaries. Important causes of arterial diseases like atherosclerosis, Buerger’s disease and diabetic gangrene are discussed in detail including pathophysiology, symptoms, method of clinical examination, investigations and treatment.