The aim of this study is to better understand age differences in well-being using Ryan, Huta, and Deci’s (2008) theory. According to this theory, four constructs are responsible for living a full and deeply satisfying life (i.e., eudaimonia) and experiencing pleasure and an absence of psychological pain (i.e., subjective well-being): (1) pursuing intrinsic goals and values, (2) behaving in autonomous ways, (3) living mindfully, and (4) behaving to satisfy the basic psychological needs for autonomy, competence and relatedness. Results indicate that aging was positively associated with the pursuit of intrinsic goals and values, autonomous behaviour, mindfulness, and mental health. Although age had a positive effect on the basic psychological need for autonomy, it had no effect on relatedness, and a negative effect on competence. The mixed influence of age on basic psychological needs may explain why older adults experienced greater levels of hedonic well-being but lower levels of eudaimonic well-being.