In this review we considered smoking cessation interventions delivered by general practitioners in consideration of their privileged position as health promoters. We selected 11 randomized trials on: a) counselling; b) nicotine gum; c) perception of health hazards in relationship with cigarette smoking. The interventions were delivered to smokers during clinical encounters. Amount of time spent by physicians during clinical encounters and number of reinforcing sessions emerged as the most important factors in a successful intervention. Nicotine gum prescription and perception of health hazards did not show any significant effect but the opportunity as reinforcing sessions.