We examined anger rumination and sadness rumination in clinic-referred adolescents (N = 121). Factor analysis indicated that items from analogous anger and sadness rumination measures loaded onto 2 factors tapping anger rumination and sadness rumination, respectively. Structural equation modeling confirmed unique relations between each form of rumination and specific emotional or behavioral problems. Anger and anger rumination were independent predictors of aggression, suggesting that both the affective component of anger (i.e., angry feelings) and the cognitive process (i.e., recurrent thoughts about anger) are important in predicting aggressive behavior. Girls reported higher levels of both forms of rumination compared to boys; however, no sex differences were found in the relations between either form of rumination and outcomes.