Children exposed to secondhand smoke (SHS) are at risk of developing ear infections, asthma, wheezing, bronchitis, as well as retarded lung growth. Indoor smoking is the main source of children's exposure to SHS. Despite a downward trend in smoking, children from low income families, especially African American and Hispanic children, continue to be exposed to SHS at a higher rate than their wealthier counterparts. This multiple case study explored the perceptions of 15 parents of 3- to 5-year-old children currently enrolled in Head Start regarding children's exposure to SHS. This study relied on the social ecological model, the theory of reasoned action, and harm reduction for understanding the views of parents and protective behaviors aimed at eliminating children's exposure to SHS in their homes. Data were obtained from semistructured individual interviews and document reviews. Data were analyzed inductively through coding to develop themes and thick rich descriptions of each case and a composite of all cases. Although participants were aware that SHS poses serious threats to the health of children, overall, they lacked knowledge of SHS exposure. They also exhibited a lack of awareness of specific illnesses associated with children's exposure to SHS. Findings from this study might help improve parents' understanding of the health risks associated with exposing children to SHS and possibly help reduce the exposure of Head Start children to SHS through the use of contextualized interventions within the Head Start community.