Smoking may cause periodontal diseases and raises the chance of getting oral cancer. The Dutch Guideline for the Treatment of Tobacco Addiction recommends that dental professionals explicitly advise all patients who smoke to stop smoking. In 12 dental practices a study was made of how the guidelines could be implemented. The strategy consisted of a patient protocol for minimal, one-time cessation advice or for more intensive supervision, a patient leaflet, centralized training for the dental team, and repeated monitoring with feedback on the patients’ experience of the behaviour that they have been advised to follow. Before the training and again 3 months after, professionals (n = 38) and an a-select sample of smoking patients (n = 197) completed questionnaires. A majority of patients was receptive to cessation advice of a dentist (95%) or counseling (68%). After 3 months it appeared that patient behaviour as reported by patients with respect to all points of the patient protocol had significantly improved.