The authors examined the relations between academic cheating and impulsivity in a large sample of adolescents enrolled in high school health education classes. Results indicated that impulsivity predicts academic cheating for students who report extensive involvement in cheating. However, students who engage in extensive cheating are less likely to report cheating when they perceive a mastery goal structure. In addition, both moderate and extensive cheaters report less cheating when they perceive the teacher as being credible. (Contains 3 tables.)