The capability approach posits that human development should be seen according to the extent to which individuals can be, do, and have whatever they value in life: an expansion of individual opportunities that could be related to the adoption of pro-environmental behaviors (PEB). The present research tested this assumption by employing two approaches for measuring capabilities (aggregated and separated by dimensions) through a normative model in an online survey among Brazilians (N = 694). The findings show that people with stronger personal norms towards the environment engage more strongly in PEB. Furthermore, the results show that, in general, the relationship of human capabilities with PEB is not strong and depends on the capabilities dimensions (general capabilities, and human needs capabilities) and specific types of PEB (general PEB, and household waste and recycling). However, these main effects were sometimes overridden by the moderating effect some capabilities dimensions have on the relationship between personal norms and specific types of PEB. In this research, the human agency capabilities dimension more consistently resonated with PEB, negatively moderating the relationship between personal norms and PEB, irrespective of the PEB type. Human needs and social being capabilities positively moderated only one relationship each, between personal norms and environmental citizenship and household waste and recycling, respectively. Therefore, specific dimensions of capabilities seem to operate as an important boundary condition for people to act upon their personal norms to behave in specific pro-environmental ways.