The understanding, prediction, and encouragement of pro-environmental behaviour (i.e., behaviour that impacts the environment as little as possible) depend to a large extent on understanding the motivational dynamics of pro-environmental behaviour. In this review paper, we discuss the state of the art with regard to these dynamics. We explain the importance of three types of goals underlying behaviour: the hedonic goal to feel good, the gain goal to enhance one's resources, and the normative goal to act appropriately. The strength of these goals differs across situation, which affects which aspects in the situation people attend to, how they evaluate these aspects, and which choices they make. We describe factors affecting the strength of goals, and how the normative goal to act appropriately can be strengthened so as to encourage sustained pro-environmental actions. More specifically, we propose that values affect the chronic strength of goals. Besides, various situational factors can affect the strength of goals in a particular situation. These situational factors explain why people do not have stable preferences and why they do not always act upon the values they prioritise. Finally, we discuss strategies that can be employed to encourage pro-environmental actions. These strategies are either aimed at reducing the conflict between different goals by aligning the hedonic and/or gain goal with the normative goal, or at strengthening the normative goal so that people will act pro-environmentally even though this may reduce the realisation of their hedonic or gain goals.