Environmental issues are some of the most pressing threats the world is facing nowadays. In this context, motivating individual pro-environmental behavior becomes highly relevant. One strategy is to harness people's pro-environmental dispositions (e.g., biospheric values, pro-environmental attitudes). Although acknowledging the need to behave pro-environmentally lies at the core of these dispositions, the extent to which they are reflected in day-to-day pro-environmental practices fluctuates to a great extent. How to bridge this gap between dispositions and behaviors in pro-environmentalism? This research tests a novel psychological solution, that is, to heighten subjective feelings of power. Power depicts people's control over their own and others? outcomes. Two studies (total N = 338, with n = 200 in Study 1 and n = 138 in Study 2) manipulated people's situational sense of high versus low power (by recalling and writing about relevant incidents), measured pro-environmental dispositions (biospheric values in Studies 1 and 2; attitude toward a specific environmental cause in Study 2), and examined their effects on pro-environmental behaviors (spending time on environmental persuasion in Study 1 and spending money on environmental donation in Study 2). Overall, both studies revealed that pro-environmental dispositions predicted pro-environmental behaviors, but only when the actors were prompted to experience a high instead of a low sense of power. The findings illuminate power as an important and viable communication tactic?to orient people toward their dispositions and practice what they preach in pro-environmentalism.