Tiebout’s (1956) suggestion that people “vote with their feet” to find the community that provides their optimal bundle of taxes and public goods has played a central role in the theory of local public finance over the past 50 years. Given the central importance of Tiebout’s insights, there have been surprisingly few direct tests of his premise. In this paper, we use a Tiebout equilibrium model to derive testable hypotheses about changes in local community demographics. The model clearly predicts increased population density in neighborhoods that experience an exogenous increase in public goods but yields only tentative predictions about the effect on neighborhood composition. To test these hypotheses, we use a difference-in-difference model to identify the effect of initial pollution levels and changes in local pollution on population and demographic composition. Our results provide strong empirical support for the notion that households “vote with their feet” in response to changes in environmental quality. This result has two implications. First, and most broadly, it provides direct empirical support for the assumptions underlying the Tiebout model. Second, in our particular application, the potential for what we call “environmental gentrification” has important implications both for the analysis of environmental equity and for the design of environmental policies aimed at benefiting the less-advantaged elements of society.