Does social identification protect or harm targets of discrimination? Two studies (N = 52, N = 94) tested the prediction that perceived legitimacy moderates the impact of social identification on negative responses to discrimination. Results confirm that when discrimination is perceived as illegitimate, identification is negatively related to self-directed anger (buffering effect) because identification provides a feeling of in-group support. However, when discrimination is perceived as legitimate, identification is positively related to self-directed anger (exacerbating effect) because the internalized social identity is perceived as legitimate target for the negative treatment. Legitimacy is measured and manipulated among different low-status groups. The legitimization and internalization of discrimination driven by self-directed anger are discussed.