Dentists can help people quit smoking because they are experts in oral health, are accustomed to counseling about oral preventive health, and have broad exposure to the general populace. To determine dentists' counseling practices with regard to smoking cessation, a randomly selected sample of 82 dentists practicing in the San Francisco Bay Area were surveyed. Also 106 internists in the same region were surveyed. Whereas the dentists believed smoking is dangerous to health and considered counseling as an important part of their practice, only 17%, compared with 58% of the internists, frequently discussed quitting with their patients who smoke. The two groups also differed in the types of counseling they used. Dentists attributed their lack of counseling to poor insurance coverage, insufficient time, lack of training, and fear that patients might leave their practices if urged to quit. These issues must be addressed if dentists are to participate fully in helping their patients quit smoking.