Background: The analysis has involved social interactions in a multicultural environment. The social context has been defined by the Vilnius region (Lithuania), where national, religious, and cultural differences exist across generations (multicultural community). The space of “social relationships”, as one of the modules of the WHO quality of life assessment, has been studied. An innovation of the research has been related to the analysis of the phenomenon of community of nationalities and cultures as a predictor of quality of life (QoL). The social motive of the research has been the historical continuity (for centuries) of the construction of the Vilnius cultural borderland. Here, the local community evolves from a group of many cultures to an intercultural community. Interpreting the data, therefore, requires a long perspective (a few generations) to understand the quality of relationships. We see social interactions and strategies for building them as a potential for social QoL in multicultural environments. Methods: The research has been conducted on a sample of 374 respondents, including Poles (172), Lithuanians (133), and Russians (69). A diagnostic poll has been used. The respondents were adolescents (15–16 years). The research answers the question: What variables form the interaction strategies of adolescents in a multicultural environment? The findings relate to interpreting the social interactions of adolescents within the boundaries of their living environment. The description of the social relations of adolescents provides an opportunity to implement the findings for further research on QoL. Results: An innovative outcome of the research is the analysis of 3 interaction strategies (attachment to national identification, intercultural dialogue, and multicultural community building) as a background for interpreting QoL in a multicultural environment. Their understanding is a useful knowledge for QoL researchers. The data analysis has taken into account cultural and generational (historical) sensitivities. Therefore, the team studying the data has consisted of researchers and residents of the Vilnius region. We used the interaction strategies of adolescents to describe the category of “social relationships” in nationally and culturally diverse settings.