We report the results of an intervention trial comparing the counseling (group A) of the general practitioner to encourage to quit smoking in dissonant smokers and an intervention based on counseling and offer of follow up at 2 and 3 weeks and at 3 and 6 months (group B). Both interventions were globally evaluated to assess the influence of the smoking habits of health professionals on the results. In the 93 group B patients there was a higher quitting rate than in group A. The rates of success after one year follow up were 26.9% and 11.9% (p less than 0.05). Forty-seven of the 152 patients were counseled by smoking physicians and 105 by non-smoking physicians; at one-year follow-up, the verified quitting rates were 10.6% and 25.7%, although the difference was not significant. It was concluded that the reinforcement of counseling by follow-up may increase the rate of quitting smoking in dissonant smokers in a primary care setting, and that the influence of the habit of the health professional can be limited through more systematic interventions.