Aim of the study is to evaluate the effects of Prostaglandin E-1 (PGE-1) in patients with peripheral arterial disease (PAD) at the 2nd b stage Fontaine's classification. The study, controlled, single blinded, enrolled 123 patients with intermittent claudication that were randomised in two groups; the first group received a treatment with PGE-1 while the second one received a pentoxifylline-buflomedil association by venous infusion. We evaluated: Pain Free Walking Distance (PFWD), Maximum Walking Distance (MWD), Rest Flow (RF), Peak Flow (PF), Basal (BVR) and Minimal Vascular Resistance (MVR) with a strain gauge plethysmograph, Resting Flow (RF), Peak Flow (PF), time to reach the Peak Flow (tPF) and time to recovery of the base values (tRF) with laser Doppler flowmeter. After a four weeks treatment, we observed an increase of 370% about PFWD and of 260% in the MWD in patients treated with PGE-1; the other group showed an increase of 110% and 118% respectively. Moreover, the patients of the first group showed a significant increase regarding the plethysmographic Peak Flow (from 9.75+/-1.37 to 16.21+/-1.75, p<0.001), greater than the one observed in the second group (from 9.53+/-1.41 to 13.47+/-1.53, p<0.05); also the laser Doppler parameters showed a significant reduction, more evident in the first group (tPF from 23.0+/-7.5 to 10.5+/-4.9, p<0.001; tRF from 73.5+/-22.7 to 48.3+/-13.5, p<0.001) than in the second one.