Smoking remains the most common preventable cause of death in the developed world, and is rapidly becoming an important cause of death in the developing world. Nicotine is a powerfully addictive substance, and the tobacco industry spends billions annually promoting it in the United States. It is therefore important for clinicians to understand why people smoke, to address smoking in patients of all ages, and to lobby for health-preserving tobacco control policies at the community level. Children take up smoking in response to social influences: smoking by friends, parents, and family, and through exposure to smoking in media. Parents who smoke not only model the behavior, but also often make the product available by leaving cigarettes around the house. Media influences include the $10 billion spent per year on tobacco marketing, but more importantly, the modeling of the behavior on screen by movie and television stars. Once children start smoking, many rapidly lose autonomy over the behavior. Youth can get hooked after smoking just a few cigarettes. The most effective community efforts for reducing tobacco use are: raising the price of tobacco; halting the sale of tobacco to minors; enforcing strict school tobacco policies; and making public places smoke free through local ordinances. Working with individuals, clinicians should support cessation in all smokers, including parents of children and adolescents. They should screen children for smoking risk factors beginning at age 10. They should teach parents to maintain smoke-free households, to set nonsmoking expectations early on, and to monitor adolescents for signs of smoking. Parents should limit exposure to adult media (e.g., R-rated movies) and use family television time to discuss the effect of seeing screen depictions of smoking on adolescent behavior. Adolescents who smoke should be assessed for signs of nicotine dependence and counseled about quitting. Clinicians are effective community voices; they should participate in efforts to raise tobacco taxes, limit the display of tobacco advertising, and make public places smoke free because of the adverse health effects of passive exposure to cigarette smoke.