Second language learners (SLLs) are students at risk for negative outcomes in preschool. Theoretical statements from systems theory and the ecological model of inclusive education indicate that a main focus of interest when supporting children should be the preschool environment that surrounds them. The purpose of this study is to describe and compare structures and processes in preschool settings that are presupposed by theory to have an impact on children’s functioning, along with children’s outcomes in preschool units with different proportions of SLLs. A combination of questionnaire data and data from observations were used in order to describe and compare the structure of child-teacher ratio, the process-related variables of teachers’ tone, children’s proximity and verbal interaction and lastly the outcomes of involvement and social interactions in different play types between the units. Data were analyzed with independent sample t-tests and the results revealed that units with different proportions of SLLs differ regarding processes and outcomes but not the structure of child-teacher ratio. Teachers’ tone in units with low proportion of SLLs was more positive and children were more verbal to the teacher while children in units with high proportions of SLL, had more self-talk/ private speech, less social-interactions and associative play, and lower levels of involvement. The differentiations in processes and children outcomes, along with the non-differences in child-teacher ratios between units with high and low proportions of SLLs highlight the need for further research in the field in order to investigate which environmental factors affect children outcomes in attempts to intervene and safeguard inclusiveness.