This study was undertaken to evaluate the efficacy and tolerability of policosanol, a new cholesterol-lowering drug with concomitant antiplatelet effects, in patients with intermittent claudication. After a baseline period of 6 weeks, 62 patients were randomized to receive, under double-blind conditions, either placebo (31 patients) or policosanol (31), 10 mg twice daily. Walking distances in a treadmill (constant speed 3.2 km/hr, slope 10 degrees) were assessed before and after 6 months of treatment. Both groups were similar at randomization. Policosanol increased significantly (p < 0.01) the initial claudication distance from 132.5+/-13.5 m (baseline) to 205.7+/-36.3 m (after therapy) and the absolute claudication distance (p<0.0001) from 229.5+/-22.0 m to 365.4+/-46.9 m; meanwhile both variables remained unchanged in the placebo group (p<0.05). The reduction of lower limb symptoms showed a greater benefit in the policosanol group. There was no significant change in either group in the ankle/arm pressure ratio. The treatment was well tolerated. There were 10 discontinuations (seven placebo, three policosanol) from the study. Six withdrawals occurred because of adverse events (AE); all were in placebo patients. There were five serious vascular AEs in the placebo group but none in the policosanol group (p<0.05). Overall, 12/31 (38.7%) placebo patients and 3/31 (9.7%) policosanol patients experienced AEs after randomization, which showed a lesser incidence of AEs in the policosanol group (p<0.01). The present study demonstrates a beneficial effect of policosanol in patients with intermittent claudication.