Past research has identified social value orientation (e.g., prosocial vs. proself) as possible underlying facilitators of pro-environmental intentions. However, recent studies have failed to draw a causal relationship using an experimental design such as priming. The current study attempted to address this issue by revisiting the relationship using a decomposed game. In addition, the current study extended the relationship between social value orientation and different aspects of pro-environmentalism (e.g., environmental attitude, identity, and self-reported pro-environmental intention). The “Attitude–Identity–Intention” path was explored in prosocial and proself groups. One hundred and fifty participants completed the decomposed game (prosocial and proself value orientations) and their respective environmental attitude, identity, and self-reported pro-environmental intentions (PEIs) were compared. We found that prosocial participants had higher levels of environmental identity, attitude, and self-reported participatory PEIs than proself participants, but not on the leadership PEIs. In addition, environmental identity mediated the relationship between environmental attitude and self-reported PEIs. This mediation only existed among the prosocial participants. The results suggest that the decomposed game is still a valid measure in social value orientation and the relationship can be extended to different aspects of environmentalism.