Lower limb peripheral arterial occlusive disease (PAOD) is highly prevalent and causes disability and poor quality of life. The purpose of our study was to evaluate the pattern of proximal and distal occlusion and collateral circulation of lower limb arteries using combined contrast arteriography and color doppler ecography. The study concerned 140 subjects (88 men and 52 women, age range 65-88 years) with symptomatic lower limb arterial disease (Fontaine's stage II) subsequent to the occlusion of vessels downstream from the subrenal aorta. The assessment of lower-extremity PAOD was performed by using the FRASI study three step protocol. The calculation of the Winsor index showed progressively lower haemodynamic compromission in distal occlusion. The more the site of occlusion was proximal, and the greater was its hemodynamic effect, although there was no statistically significance. A combined use of contrast arteriography and color doppler ecography appeared very useful in studying the anatomy of the occlusions and their haemodynamic impact, as well as in analysing the presence and the effects of collateral circles. These findings may be fundamental for identifying the most correct indications for surgical therapy and for selecting optimal strategies and prostheses.