Previous research about social dilemmas has identified cooperation as a possible underlying facilitator of proenvironmental behavior. However, there has been no discussion about how manipulating cooperation and competition could influence environmental action experimentally. The current study filled this gap in previous literature by manipulating cooperation and competition in a group of 155 participants and comparing their respective environmental actions. Participants were randomly placed into one of three conditions and primed by writing a short passage regarding a significant personal experience where they acted cooperatively, competitively, or neutrally. It was found that those in the cooperative priming group scored significantly higher on environmental participatory action than people in the competitive priming group. However, no difference was found on environmental leadership action. The results indicated that participatory environmental actions are relatively easier to change, as the threshold for interest in them is much lower than leadership environmental actions.