Twenty-seven patients with peripheral atherosclerotic disease were randomized into two therapy regimens consisting of indobufen (Indo) (400 mg/day) and dipyridamole (Dip) (225 mg/day) plus acetylsalicylic acid (ASA) (1 g/day), respectively. Maximal walking distance (MWD) and ankle-arm systolic pressure ratios were measured before and after three and six months of therapy; bleeding time, beta-thromboglobulin (beta-TG), platelet factor 4 (PF4) and serum thromboxane B2 (TXB2) were also assessed. The two treatment groups showed a significant and progressive increase in pain-free walking distance at both three and six months of therapy, but patients taking indobufen showed a greater improvement. On the contrary, the pressure doppler ratio at rest was statistically improved only in the ASA plus Dip group. Basal beta-TG and PF4 levels were normal and no changes occurred during the study in either group, while in all patients bleeding times showed a significant increase above basal values and serum TBX2 decreased.