Ego depletion refers to a state where self-control capacities are diminished, which subsequently affects behavioral responses that rely on self-control. The current study is the first to investigate ego depletion as an underlying process in the link between rumination and aggressive behavior. Aggression is indicative of self-control failure because it involves the inability to restrain aggressive impulses. The study employed a 2 (Provocation: Yes/No) x 2 (Rumination: Provocation-Focused Rumination/Distraction) between subjects design. Consistent with expectations, provocation and rumination significantly interacted such that provoked participants who ruminated exhibited significantly (1) less self-control resources and (2) more aggression relative to the combination of the other experimental conditions. Furthermore, self-control partially mediated the effect of provocation and rumination on aggressive behavior. Lastly, negative affect partially mediated the relationship between provocation-focused rumination and self-control.