Existing research explains pro-environmental behavior as being motivated by personal values. In this article I extend this framework to examine not just the choice of whether to engage in pro-environmental behavior but also the choice between different pro-environmental behaviors. I argue that if several different pro-environmental behaviors all express the same personal values, and carry the same material costs, then individuals choose between them on the basis of their expected policy consequences. I report the results of a survey experiment showing that priming individuals to consider instrumental utility will cause over-reporting of some forms of environmental activism—those with the greatest expected policy impact. This prime will have no effect on over-reporting of other forms of activism. I conclude that instrumental utility is an important part of how individuals choose between types of pro-environmental political activism.