This work focuses on the teacher training case-based for preventing the refugee students' marginalisation. Some key-elements in prevention of marginalisation in school are presented in the first part: the holistic descriptive model and the difficulty in resorting to practical-based strategies for teachers training. A professional research study conducted in 2023 at the post-graduate training course is presented in the second part. The study involved 110 teachers and investigated the effectiveness of case-based training, specifically, how much it favours teachers' ability to grasp the multilevel factors useful for avoiding the marginalisation of refugee students. The results provide arguments in favour of case-based teacher training in classroom reception. The case-based method could help teachers to understand the complexity of the integration processes of refugee students within the classroom and to take on the necessary multilevel perspective. The analysis also reveals the prevalence of the student-teacher relational level.