This investigation examines the ability of the theory of reasoned action (TRA) to explain and predict adolescents' verbal (i.e., insulting) and physical (i.e., fighting) aggression, as well as behaviors that encourage aggression such as watching a fight or telling others about a fight that is going to happen. Subjects were 488 seventh-grade boys and girls enrolled in 2 public junior high schools in a large Midwestern U.S. city. Subjects completed a survey assessing components of the TRA as they related to the 4 behaviors under investigation. Consistent with the TRA, analysis revealed that attitudes and subjective norms predicted behavioral intent, and intent predicted behavior, for watching a fight, spreading rumors about a fight, and insulting. For fighting, however, attitudes, but not subjective norms, predicted behavioral intent, and intent predicted behavior. Implications for the TRA as well as for the development of youth violence prevention and intervention programs are discussed.