The aim of this study was to investigate why certain youths identify with delinquent groups by examining specific factors that increase identification with them, such as intergroup relationships. Specifically, we hypothesized that the permeability of group boundaries would moderate the effect of group discrimination on identification with a delinquent group. In total, 96 male youths were recruited from four juvenile classification homes. The results revealed that youths who perceived group boundaries with lower compared with higher permeability cognitively identified with delinquent groups more strongly when perceiving group discrimination from teachers or the police; this finding supported our hypothesis. No other significant interaction effect was observed. Conversely, in terms of affective identification, we found an unexpected interaction between the permeability of group boundaries and group discrimination from peers. Overall, the findings did not support our hypothesis. However, some of the results suggest that delinquent youths may be able to decrease cognitive group identification by having friends outside of the delinquent group, even if they experienced discrimination from conformity groups such as teachers and the police.