Tobacco Purchase-Use-Possession laws (PUP) are being implemented throughout the US, but it is still unclear whether they are effective in reducing smoking prevalence among the youth targeted by these public health policies. In the present study, 24 towns in Northern Illinois were randomly assigned to one of two conditions. One condition involved reducing commercial sources of youth access to tobacco (Control), whereas the second involved both reducing commercial sources of youth access to tobacco as well as fining minors for possessing or using tobacco (Experimental). Students in 24 towns in Northern Illinois in the United States completed a 74 item self-report survey in 2002, 2003, 2004 and 2005. At the start of the study, students were in grades 7-10. During each time period, students were classified as current smokers or nonsmokers (i.e., completely abstinent for the 30 consecutive days prior to assessment). The analyses included 25,404 different students and 50,725 assessments over the four time periods. A hierarchical linear modeling analytical approach was selected due to the multilevel data (i.e., town-level variables and individual-level variables), and nested design of sampling of youth within towns. Findings indicated that the rates of current smoking were not significantly different between the two conditions at baseline, but over time, rates increased significantly less quickly for adolescents in Experimental than those in Control towns. The implications of these findings are discussed.