This commentary on S. A. Pyle, C. K. Haddock, N. Hymowitz, J. Schwab, and S. Meshberg (2005) addresses the complex nature of establishing family rules about exposure to tobacco smoke (ETS). Particular attention is paid to how family rules are established and the challenges in enforcing rules among adult family members. Findings are also discussed in terms of the limits of family rule making and the need for negotiation and conflict resolution. The compounding influence of socioeconomic status and parental education in monitoring ETS deserves serious attention in future research. Healthcare providers are urged to discuss family rules with their patients with an eye toward preventative interventions.Families are responsible for establishing a variety of rules: How much TV viewing is allowed, bedtime on school nights, curfews, when a child can have dessert, and who gets to sit in the front seat of the car on a long trip are but a few examples of everyday family rules. In their article, Pyle, Haddock, Hymowitz, Schwab, and Meshberg (2005) have brought to our attention the establishment of family rules about exposure to environmental tobacco smoke (ETS). The results of this study are important as well as somewhat disturbing in terms of the amount of exposure that occurs in households and family vehicles. As the authors pointed out, exposure to ETS is a public health problem of grand proportion. It threatens the health and well-being of children and adults at risk for respiratory illnesses and can also contribute to the development of disease. The establishment of rules about exposure to tobacco smoke is not a simple issue. The authors have added to a small but growing literature suggesting sociodemographic variations in exposure to tobacco smoke. Consistent with previous reports, lower levels of education and minority status were associated with greater exposure (Wamboldt et al., 2002). What Pyle et al.'s study adds is a description of the types of rules that families endorse. It also raises the issue of who makes the rules and examines the limits of family rule making. I address each issue in turn.