In this paper selected key results of the Swiss MIRIPS study (Mutual Intercultural Relations in Plural Societies) will be presented. In our study we developed a three-dimensional concept of acculturation including a minority orientation, a mainstream orientation and a multicultural orientation. We will examine how different acculturation strategies of immigrant youth affect their psychosocial adaptation (life satisfaction, sociocultural competence, self-efficacy) and their school success (reading skills in the local language of instruction, school satisfaction, educational aspirations, school-related misconduct). The sample consists of secondary school students (n=1488) who live in urban areas of German-speaking Switzerland focusing on Italian, Portuguese and Albanian students. For the data collection a student questionnaire, a teacher questionnaire and a German reading test from the PISA study were administered. The data was analyzed by means of multilevel regression models. The results indicate that a combination of all three strategies (integration) examined in this study as well as the minority orientation alone (separation) have a positive impact on certain aspects of psychosocial adaptation. Regarding school success the multicultural strategy alone or in combination with the minority orientation (partial integration) turned out to be the preferred strategy of the higher achieving and better adapted students.