Research suggests that perceived ethnic discrimination is associated with poor psychological and physiological health. Rumination, or perseverative thoughts about negative experiences, may constitute a maladaptive coping strategy that mediates the associations between perceived discrimination, emotional distress, and aggression. Our sample consisted of 170 ethnic minority and 134 White American participants. For ethnic minority participants, we found a pattern of correlations consistent with rumination partially mediating a causal link between perceived discrimination and depressive symptoms, hostility, anger, and aggression. In White participants, by contrast, the significant associations between perceived discrimination and these indices of emotional and behavioral distress were not statistically mediated by rumination. We discuss possible theoretical and clinical implications of these results.