This study examined how mechanisms of moral disengagement (MD) were related to students’ self-reported misbehaviors. Participants were 282 and 336 high school students enrolled in physical education classes. In Stage 1, results of regression analysis showed that advantageous comparison and non-responsibility positively predicted four misbehaviors (i.e., low engagement, failure to follow directions, poor self-management, and distracting behavior). In Stage 2, results of the structural equation modeling confirmed that advantageous comparison and non-responsibility were the significant predictors of student misbehavior in physical education. It is suggested that prevention and intervention programs should address students’ advantageous comparison (e.g., compared to skipping class, it is not a big deal to be shirking in class) and non-responsibility (e.g., no one is taking the class seriously; I am just one of them) to reduce misbehaviors in the physical education context.

• The mechanisms of moral disengagement have been applied in recent studies on behaviors during physical activities, supporting the idea that moral disengagement in individuals is significantly correlated to their negative behaviors.

• The mechanisms of advantageous comparison and non-responsibility positively predicted misbehaviors in physical education.

• Prevention and intervention programs should also address advantageous comparison and non-responsibility in order to reduce students’ misbehavior in the physical education context.