Objectives: Group-level characteristics in shared contexts such as schools may affect adolescent psychological health. This study examined if the immigrant density in the classroom was associated with the level of self-reported psychological complaints among students with an immigration background.

Methods: Cross-sectional data were derived from 2,619 lower secondary school students (aged 13-15) in the 2017/18 wave of the Swedish Health Behaviour in School-aged Children (HBSC) survey. Using multilevel analysis estimating two-level random intercept linear regression models, classroom immigrant density was considered as a potential predictor of immigrant students' psychological complaints.

Results: Students with an immigration background reported significantly fewer psychological complaints, on average, than students without such a background, even when adjusting for other sociodemographic characteristics. A cross-level interaction indicated that both first- and second-generation immigrant students experienced fewer psychological complaints in immigrant-dense classes compared to when the proportion of immigrant students was lower.

Conclusion: Students with an immigration background fare better psychologically in classes with a higher proportion of immigrant students. Such compositional effects could be alleviated by strengthening all schools' capacities to provide a more inclusive classroom climate.