The postmaterialism hypothesis suggests that wealthy countries are likely to be early adopters of pollution control regulations. Yet, Global South countries have taken the lead in regulating plastic bags. To explain this puzzle, we examine the influence of plastic waste imports on the onset of domestic plastic bag regulations. Processing imported waste creates visible local pollution in the Global South and mobilizes citizens and environmental groups. Because plastic bags are a visible manifestation of the plastic pollution problem, they become focal points for regulatory action. Using a hazard model, our analysis of 133 countries for the 1992–2019 period suggests that plastic waste importers (located in the Global South) are more likely to regulate plastic bags (via fees or bans) earlier, while plastic waste exports are not associated with plastic bag regulation. This article raises broader theoretical issues about domestic policy spillovers of international trade and addresses how trade might unexpectedly activate domestic politics focused on postmaterialist concerns.