Background: In efforts to curb and prevent youth smoking, school tobacco policies have become an important and effective strategy. This study explores the degrees and types of tobacco-free school policy (TFSP) enforcement that are associated with adolescent smoking. Methods: A multilevel analysis was performed using 983 students who are nested in 14 schools. The individual-level data are drawn from the 2009 Michigan Youth Risk Behavior Survey. The school-level data are drawn from the 2008 School Health Profiles survey. Results: Two factors are associated with lower adolescent smoking: greater punishment for TFSP violation and more tobacco control communication efforts. By contrast, the factors associated with higher adolescent smoking are designation of a tobacco-free school zone and school-level smoking. Conclusions: This study theoretically and methodologically guides researchers to test TFSP effectiveness in other states. Three strategic implications emerge: (1) schools should provide a consistent anti-smoking message in smoke-free environments; (2) schools should integrate TFSP into a comprehensive tobacco control initiative, including community-wide tobacco control programs and messages; and (3) the way a specific TFSP is promoted and communicated could determine how effective it is.