Despite abundant evidence about the adverse effects of secondhand smoke exposure on children's health, few reports describe barriers and facilitators encountered by parents in making their homes and vehicles smoke-free. This article describes perceptions of barriers and facilitators to making homes and vehicles smoke-free among 36 parents with a child five years of age or younger. Qualitative data were collected in interviews with parents in the context of a randomized controlled trial that tested an intervention to empower parents to make their homes and vehicles smoke-free. Themes that emerged in the analysis were congruent with an ecological conceptualization of health. The greatest barriers were intrapersonal factors, and nicotine addiction was the intrapersonal barrier identified most frequently. The most frequently reported facilitators were intrapersonal factors, such as quitting smoking. Parents reported not seeking advice from health care providers. The transition process to make homes and vehicles smoke-free is complex and individualistic; nurses may need to tailor strategies to take the specific contexts of each individual into account.