Doppler US is a first choice instrumental examination for the diagnosis and staging of peripheral arterial occlusive disease in diabetic patients. Doppler US is a noninvasive, reproducible and cost-effective procedure. Grey-scal images identify plaque and thrombus, duplex assessment provides a measurement of blood velocity through a vessel, and color Doppler imaging enables the rapid localization of arterial stenoses and occlusions. Direct morphologic and flowmetric evaluations of stenotic-occlusive alterations, and direct evaluations based on the interpretation of velocimetry findings proximal and distal to the lesions, are feasible. The conventional basic examination can be enhanced with the power module. Disadvantages of the procedure are related to the poor panoramic view, subjective (operator-dependent) interpretation and limitations related to the physics of ultrasound.