Background: Relatively little research has focused on the social norms of teen smoking. This study examined social norms regarding adolescent smoking and their relationship with smoking behavior. Methods: Data were collected in 1998 as part of the follow-up for a randomized trial in 14 rural Minnesota communities. Four aspects of perceived social norms of smoking were measured, and students were classified as nonsmokers, daily smokers, past-week smokers, or past-month smokers. Social norms were compared across four levels of smoking behavior, and multivariate models controlled for personal characteristics and family and peer smoking. Results: The sample comprised a total of 3128 girls and 3146 boys in grades 8 to 10. For all four measures, nonsmokers had the most antismoking perceptions of social norms around smoking (p <0.001). In multivariate models, noticing other teens smoking and the perception that adults care about and disapprove of teen smoking remained significantly related to past-month smoking. Using more frequent smoking as the dependent variable, noticing smoking remained significantly associated with smoking in the anticipated direction. Perceived prevalence of smoking did not perform consistently across models. Conclusions: Noticing teens smoking is associated with smoking behavior across three different levels of smoking frequency. The perception that adults care about and disapprove of teen smoking was associated with past-month and past-week smoking. Although perceived prevalence is often used to measure social norms of teen smoking, this measure may have limited utility. Strategies for health promotion and intervention on the issue of youth smoking are discussed.