Although pro-environmental behaviour is often believed to be difficult, aggravating, and potentially threatening one's quality of life, recent studies suggest that people who behave in a more pro-environmental way are actually more satisfied with their lives. In this manuscript, we aim to explain this apparent paradox by reviewing theoretical arguments and empirical evidence for both sides of the coin: why would acting pro-environmentally decrease one's well-being, and why would it increase one's well-being? We conclude that part of the answer lies in a different view on what well-being entails, and more specifically, whether the focus is on hedonic well-being (i.e., feeling pleasure) or eudaimonic well-being (i.e., feeling meaningful).</p