Collective deprivation, connectedness to mainstream society (friendship and psychological closeness to majority individuals) and in-group identity factors (i.e. strength of in-group identity, and perceived in-group superiority) were investigated among Muslim Dutch youth of Turkish and Moroccan descent, in relation to their attitudes toward violence in defense of religion or ethnicity, and the willingness to use such violence. Data come from a sample of students (N=398, age 14-18 years). Results show that perceptions of in-group superiority were predicted by higher connectedness to the in-group and lower connectedness to Dutch society in both ethnic groups and by collective relative deprivation among Moroccan-Dutch participants only. In both groups, attitudes toward violent in-group defense and violence willingness were predicted by perceptions of in-group superiority. Collective relative deprivation directly predicted more positive attitudes to violent in-group defense among Turkish-Dutch youth, as well as indirectly (via in-group superiority) among Moroccan-Dutch. Connectedness to the in-group directly predicted the willingness to use a violent in-group defense among the Turkish-Dutch participants and again indirectly (via in-group superiority) among Moroccan-Dutch participants. The results underline the relevance of collective identification processes to the attitudes of violent in-group defense among young Muslims of the second generation in a rather tensed socio-political climate. The study outcomes emphasize the importance of examining the dynamics between different Muslim groups, as their unique acculturation patterns yield particular pathways to the attitudes toward violent in-group defense and the willingness hereof.