Public policies concerning tobacco shape the environment of the smoker and nonsmoker alike. These policies use diverse means to achieve the common goal of reducing tobacco use and its attendant health consequences. Educational interventions such as warning labels, school curricula, and public service announcements serve to inform the public about the hazards of tobacco smoke. These are countered by the pervasive marketing of tobacco products by the tobacco industry, despite a ban on tobacco advertising on radio and television. Further restrictions on tobacco advertising and promotion have been proposed and await action. Cigarette excise taxes and smoker-nonsmoker insurance premium differentials discourage smoking by making it more costly to purchase cigarettes. Conversely, health insurance reimbursement for smoking cessation programs could reduce the cost of giving up the habit and might encourage cessation. Restricting or banning smoking in public places and workplaces decreases a smoker's opportunities to smoke, further inhibiting this behavior. Reducing the availability of cigarettes to children and adolescents may help to prevent them from starting to smoke. The environment of the smoker is conditioned by this pastiche of influences. Physicians who become involved in tobacco-control issues have the opportunity to alter the environmental influences on their patients. This is likely to be synergistic with physicians' efforts inside the office to encourage individual smokers to quit. As a first step toward advocacy outside the office, physicians can help to create a smoke-free health-care facility in their own institution. Beyond that, advocacy groups or the voluntary health organizations (e.g., American Lung Association) provide avenues for physicians to take a stand on community issues relevant to tobacco control. Physicians who take these steps to alter the environment of smokers beyond the office are likely to magnify the effect of their work with individual patients who smoke.