Angry rumination is perseverative thinking about a personally meaningful anger-inducing event and is a risk factor for aggression. This article presents a new model for understanding angry rumination across five levels of analysis: cognitive, neurobiological, affective, executive control, and behavioral. The type of rumination that occurs at the cognitive level moderates affective responding and neurobiological activation, which influences executive control and aggression. Angry rumination recruits brain regions implicated in cognitive control, emotion regulation, negative affect, physiological arousal, social cognition, and self-reflection on emotional states. Moreover, angry rumination temporarily reduces self-control, which can increase aggression. The article suggests a functional account of angry rumination, identifies gaps in our knowledge, and proposes future research directions based on hypotheses derived from the model.