A person-centered exploration of positive emotions in relation to self-determination theory might shed light on the hidden dynamics in the motivational processes in physical education (PE). In the present longitudinal study, PE students were followed during three years at secondary school (N = 1681). Latent class growth analysis revealed a three-class solution: The largest class (n = 1121) reported high levels of positive emotions over the three years. The second largest class (n = 275) reported low levels of positive emotions over the three years, and the smallest class (n = 112) reported a decrease in positive emotions over the three years. Further, the results revealed an association between the intensity of positive emotions, satisfaction of basic psychological needs, and quality of motivation. This person-centered study contributes to the identification of students' emotional engagement in PE as an indicator for understanding their processes of learning, development, and well-being.