This article examines cross-cultural differences in the value cluster of environmentalism and postmaterialism. Based on an extension of Ronald Inglehart’s “objective problems–subjective values” hypothesis, we posit different sources of postmaterialism and environmental concern in wealthy versus poor countries. We test hypotheses on the relationship between national wealth, postmaterialist values, and environmental concern using empirical data from the World Values Survey waves 5 and 6 and the International Social Survey Program 2010. Using multilevel regression models with cross-level interaction terms and country fixed effects, we show that the effect of postmaterialism on environmental concern is indeed moderated by national wealth: whereas there is a weak or even no effect in poorer countries, the relationship is substantial in wealthy countries. Therefore, we argue that individual postmaterialist values and environmental concern do in fact form a coherent structure in wealthy countries, but should be considered as isolated constructs in poorer countries.