The efficacy of a medicinal herb tea (MHT) for assisting smoking cessation and for reducing withdrawal symptoms was evaluated by a placebo controlled subjective test in 100 male smokers. The MHT group experienced less craving for the taste of tobacco, and was more successful at quitting smoking. Among the subjects continuing to the final stage, 23 subjects (38.3 %) who took the MHT and 2 subjects (10.0 %) who took the placebo tea succeeded in quitting smoking. In the group taking MHT, urinary cotinine concentration increased during the first 2 weeks and then greatly decreased from weeks 2 to 4. The urinary cotinine concentration in the MHT group at week 0 was 38.6 mol/L but decreased to 24.5 mol/L by the end of week 4. MHT also reduced withdrawal symptoms, a frequent reason for failure in reducing or quitting smoking. The effects of the herbal tea on smoking cessation and withdrawal symptoms may be attributed to increased metabolism of nicotine and other effects of unidentified components of the herbal ingredients.