Drawing from theory and research into social comparison processes, the present study sought to determine children's motives for comparison in addition to the coexistence of class and individual comparisons in school physical education. The main and interactive effects of these types of comparisons were examined in relation to pupils’ physical self-concept, as well as self-reported behavioral engagement and disaffection in class. In total, 545 children (Mage = 13.89 years, SD = 1.57 years) from two schools in England completed the questionnaire. Moderated hierarchical regression analysis demonstrated that the higher a child's perception of his or her ability was compared with his or her classmates, the greater the level of engagement and physical self-concept and the lower the level of disaffection. Interaction analysis showed that when perceived ability with reference to the class was low, a downward comparison with an individual enhanced engagement, but this was not the case when perceived ability was high. Findings suggest that further research into social comparison processes in this setting is warranted.