Despite decades of debate on environmental justice, analyses of the causal mechanisms have often been restricted to spatially aggregate data and a single context. We thus still lack a detailed understanding of how and to what extent selective residential migration contributes to environmental inequality. We link geo-referenced longitudinal household-level data from the German Socio-Economic Panel (GSOEP) and the UK Household Longitudinal Study (UKHLS) to air pollution estimates, including nitrogen dioxide (NO2), particulate matter (PM2.5), and sulphur dioxide (SO2). In both countries, immigrant minorities are exposed to higher levels of air pollution around their place of residence. Given the initial disadvantage of immigrant minorities, we would expect them to experience larger improvements from relocations over time. However, we show that this is not the case using household fixed effects models conditioning on the initial pollution level. If a native household started in a similar situation as immigrants do, they would experience much higher relocation gains. This process is similar in Germany and England, but the general disadvantage as well as the differences in returns or residential mobility are stronger in England. We also show that immigrants’ lower average income is not the driving force behind their environmental disadvantage.