Physicians have an important responsibility for addressing smoking cessation and prevention with their patients. The objective of this study was to describe the use of physician counseling for the prevention and control of smoking and to predict its use according to physician characteristics. A cross-sectional survey of a random sample of 121 family physicians in one municipality of the city of Havana was used to address sociodemographic factors, years of practice in the community, smoking status, use of physician counseling in daily practice (ask, advise, and assist), and the role of physician counseling as an intervention. Summary statistics were used as well as canonical and discriminant analyses. The prevalence of smoking among the physicians was 18%. The smoking status of patients was determined "almost always" by 32% of doctors. Twenty-five percent asked their patients whether they intended to stop smoking; 35% recommended smoking cessation; and 38% gave advice on how to achieve this. More than half (58%) explored factors that might influence cessation in their patients, and 12% reported doing this "frequently." Physician characteristics were associated significantly with preventive behavior, with community involvement, and with the perceived value of physician counseling and smoking status. Physician responses were associated with actual practice in 82% of the cases. Predisposing, facilitating, and reinforcing factors for preventive behavior were strong determinants of active involvement by physicians in daily practice. Training of health professionals must include smoking cessation.