The aim of this trial was to assess the activity of indobufen compared with placebo in peripheral occlusive arterial disease of the lower limbs of atherosclerotic or diabetic origin. Fifty-two outpatients were admitted to the randomized, double-blind study and were given either an indobufen 200-mg tablet (28 subjects) or placebo (24) for six months. Painfree walking distance on a treadmill at a constant speed (4 km/h) and slope (10 degrees) was assessed before and after three and six months' treatment. The painfree walking distance before treatment with indobufen or placebo averaged 153 +/- 23.02 (mean +/- SE) and 199 +/- 30.58 (mean +/- SE) meters respectively. After six months' treatment with active drug or placebo, this parameter reached 610 +/- 115.36 (p less than 0.01) and 243 +/- 32.49 (p greater than 0.05) meters respectively. The difference between the two treatments was statistically significant in favor of indobufen (p less than 0.01 Dunn's test).