This article is the third in a series of four providing up-to-date information about the tobacco problem and how physicians can effectively intervene. Three of the four articles are accredited for free continuing medical education (CME) credit for physicians. To obtain AMA PRA Category 2 Credit for this article, please go online to www.pedseducation.org, your source for free Continuing Medical Education from Nemours. Choose Online Education, the article, and complete the post-test as directed. CME accreditation for this educational presentation is provided at no cost as a service of Nemours, one of the nation's largest children's health systems. Nemours is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physcians. Nemours designates this educational activity for a maximum of .5 AMA PRA Category 1 Credit(s). Physicians should only claim credit commensurate with the extent of their participation in the activity. This article reviews the health effects of adult smoking on children. It focuses on the impact of environmental tobacco smoke (ETS). By reading the article and completing the post test it is anticipated that the following learning objectives will be met: 1) physicians will become familiar with the health effects of ETS on children, 2) physicians will become familiar with parental knowledge gaps and at risk populations and 3) physicians will understand the benefits of addressing the issue of adult smoking with parents.