This article forges a link between support for European integration and adoption of tobacco advertisement restrictions in Swiss cantons. Leaning on the policy diffusion literature, this article argues that the more voters support deeper European integration, the more likely cantonal governments are to restrict tobacco advertising. Policymakers use voters' support for more European integration as a signal that they support regulatory policies that are strongly associated with the European Union (EU) in the political and media debate, such as tobacco advertisement bans. This effect ought to be especially strong in the absence of adverse economic interests, such as the presence of the tobacco industry. To buttress these claims, the present article uses statistical analysis, specifically event-history analysis. Apart from the insights about Swiss tobacco control policy, this article contributes to our understanding of indirect EU influence on cantonal policymaking and policy diffusion.