Among many studies on cytisine only a few have been controlled trials, and the aim of this study was to assess the efficacy of cytisine in a randomized controlled double-blind trial compared to placebo in medium-dependent smoking men working in mining industry. Materials and methods: 171 middle-aged smokers were randomised to either cytisine (25-days regimen) or placebo; both groups received individual counseling with brochure. Self-reported continuous abstinence was assessed at 8 and 26 weeks. Results: At the end of week 8 there were no differences in number of abstinent subjects, but at 26 weeks 10.6% of subjects were abstinent in cytisine group compared to 1.2% in placebo (p = .01). In both groups, we did not find any weight increase, but quality of life improved in both groups, and physical and social functioning improved in cytisine group. Conclusions: Cytisine may be an effective medication to help smokers quit even for those working in difficult working conditions with high relapse rate.