This paper reports on a double blind trial of the effect of buspirone, 15 mg per day, on cigarette withdrawal symptoms and ability of smokers to maintain abstinence during treatment. A total of 61 smokers were randomly assigned to active or placebo conditions. They were maintained on their drug for 2 weeks prior to attempting abstinence and then for a further 4 weeks of abstinence. Subjects attended weekly group sessions of a psychological treatment programme. There was no evidence that the side effects in the active drug group were worse than those in the placebo group. Although there was no significant difference between active and placebo conditions on withdrawal symptoms, smokers in the active drug condition were more than twice as likely to maintain abstinence for the duration of the study than those in the placebo condition (47% versus 16%, chi square = 5.3, P less than 0.025). The results provide preliminary evidence for short-term efficacy of buspirone as an aid to smoking cessation at a low dose. They also provide evidence of a dissociation between withdrawal symptoms and successful abstinence.