Interpersonal provocation is a common and robust antecedent to aggression. Four studies identified angry rumination and reduced self-control as mechanisms underlying the provocation-aggression relationship. Following provocation, participants demonstrated decreased self-control on an unpleasant task relative to a control condition (Study 1). When provoked, rumination reduced self-control and increased aggression. This effect was mediated by reduced self-control capacity (Study 2). State rumination following provocation, but not anger per se, mediated the effect of trait rumination on aggression (Study 3). Bolstering self-regulatory resources by consuming a glucose beverage improved performance on a measure of inhibitory control following rumination (Study 4). These findings suggest that rumination following an anger-inducing provocation reduces self-control and increases aggression. Bolstering self-regulatory resources may reduce this adverse effect.