Diagnosis and treatment of lower limbs arterial disease do not depend exclusively on functional staging. Fontaine's classification has to be replaced by a classification based on clinical and complementary investigations to understand better the evolutive risks, and guide management. Distal systolic pressures along with symptom analysis and clinical examination allow a more precise diagnosis. Complementary investigations aim at assessing, the localization and extension of atherosclerotic lesions; the severity of tissue ischaemia. The concept of critical ischaemia has tried to insure greater diagnostic homogeneity for patients with rest ischaemia. The role of complementary investigation can only increase for the diagnosis and management sclerotic arterial disease. The detection of the other localizations of atherosclerosis and arteriosclerosis are essential to prevent complications which are responsible for the prognosis of the disease. Sclerotic arterial diseases represent approximately 90 to 95% of the causes of arterial diseases. Identification of these other causes remains, however, essential as it can greatly influence prognosis.