A multicentre, double-blind, crossover study monitoring walking distance and symptomatology was set up to compare the efficacy of cinnarizine with that of placebo in the treatment of patients with intermittent claudication. Walking distances were statistically significantly increased by cinnarizine treatment when it was given before placebo. This improvement was maintained without further significant deterioration when the patients were switched to placebo therapy. A smaller but statistically significant increase in walking distance was observed after the first 12 weeks of tarizine treatment an additional increase in mean walking distance, comparable to that seen during the first half of the study, was observed in these subjects. This improvement failed to reach a level of statistical significance because of the variation in response between individual patients.