Background: Recent theoretical approaches emphasize adolescents’ active skills and agency in developmental processes and propose that immigrant adolescents may be the socializing agents for their families in new environments. However, empirical research on immigrant adolescents’ active role in the family reveals some research gaps. The overarching goal of this dissertation was to investigate immigrant adolescents’ active role in family adaptation and determine how it is related to adolescent and familial psycho-socio-cultural adjustment. Specifically, to achieve this goal, I examined different forms of adolescents’ involvement in family processes as well as its associations with risks and opportunities for adolescent and family adaptation and interactions. I also aimed to identify factors that can explain differences in immigrant adolescents’ active role across families, including migration conditions and acculturative timing.Methods: Adolescents’ active role in the family was investigated by considering two types of active youth involvement in family processes: activities by which adolescents directly support their families (termed direct adolescent influence) and ones in which adolescents’ developmental progress unintentionally provokes family reactions (termed evocative adolescent influence). To examine adolescents’ active role and its hypothesized relations and outcomes, I drew on two cross-sectional and one longitudinal data set containing parent–adolescent data from five ethnic groups (native Germans, native Swiss, German immigrants, ethnic German repatriates, Russian Jews) in three contexts (Germany, Israel, Switzerland). The data were analyzed using person-oriented, comparative, and multi-group approaches as well as structural equation modeling in Mplus and SPSS. Results: The analyses revealed substantial levels of direct adolescent involvement in families in the form of migration-specific (i.e., brokering) and migration-unspecific support (i.e., instrumental and emotional support). In addition, adolescents who provided migration-specific support were shown to provide more direct support in families in general. Evocative adolescent influence was confirmed through relations of adolescents’ independent acculturation with family interactions. Adolescents’ active role in family processes was supported in all studies independent of ethnic group or context and in host and ethnic culture domains. Notably, the analyses revealed that adolescents’ active role can be a double-edged sword for family adjustment with both positive (e.g., self-efficacy, child disclosure) and negative (e.g., exhaustion, family hassles) adolescent and family outcomes. Further, group- (e.g., family resources) and context-characteristics (e.g., segregation) can foster adolescents’ active role in families. Finally, adolescents’ acculturative speed as well as parent-adolescent differences in acculturative timing were shown to strengthen associations of adolescents’ acculturation and family dynamics.Conclusion: Adolescents are active agents creating their own development in multicultural societies and can contribute substantially to successful family adaptation. In this respect, this dissertation provides insights into the active and constructive roles that adolescents can adopt in families and societies and discusses implications for future research and practice.