This manuscript describes the tobacco industry's efforts to recruit active smokers among the adolescent population, the effects of environmental tobacco smoke on nonsmokers, and lists some steps pediatricians can take to influence smoking behavior. Six health effects result from passive smoking. Children exposed to environmental tobacco smoke have increased lower respiratory illness rates, especially in the first year of life, passive smoking is associated with increased rates of chronic middle ear effusion in children. Exposure to cigarette smoke is associated with small changes in pulmonary function. Exposure to environmental tobacco smoke increases an asthmatic child's exacerbations. Exposure to environmental tobacco smoke is a risk factor for sudden infant death syndrome. Passive exposure during childhood to a parents smoking increases a child's risk of leukemia and lymphoma during adulthood. Pediatricians and others who care for children must try to limit as much as possible, the exposure of children to the cigarette smoke produced by others.