Quebec is experiencing a significant increase in immigrants, especially outside the metropolis (ISQ, 2017; Bakhshaei, 2015). Schools are, therefore, at the center of debates relating to the various issues inherent in diversity. However, they still lack "intercultural practices," which are more deeply rooted in the Montreal school environment than elsewhere in the province. In addition, regulatory writings do not adopt the issue of school diversity as it is represented today in schools. In addition, various research on the international scale underlines that immigrant students are likely to fail or obtain poor academic results compared to non-immigrant youth (Kamanzi et al., 2016). Thus, more than ever, the school administration must exercise its leadership to support good collaboration between school and social actors. It is about staying focused on the educational success of all students. The magnitude of this reality requires collaboration on the school, immigrant families and the community. The general objective of this thesis is to analyze the practices of school-immigrant families-community (ÉFCI) collaboration. Three specific purposes form this general objective, subject to three publications. - The first specific objective consists of identifying and describing the collaborative practices that the members of the community organization Centre Multiethnique de Québec (CMQ) put in place to promote the integration of immigrant families and academic and educational success of their children. This goal is the subject of a book chapter published in Immigration et Nouvelles vies at Presses de l'Université Laval. Two concepts support this qualitative study, support and leadership. We realized a document study to carry out this research. These are 13 documents published by the said center, spread out between 2015 and 2018. The analysis of these documents made it possible to identify the presence of practices linked to the individual and collective support of newly arrived families and their children. In addition, it turned out that the CMQ never stops making efforts to meet their expectations and give them a feeling of confidence and security (training, funding, new services, etc.). - The second specific objective is to identify and analyze ÉFIC collaboration practices and the types of links of this collaboration to promote immigrant students' academic and educational success. The conceptual framework of this qualitative study is the approach of the bioecological model of Bronfenbrenner (1979) and the six dimensions of the shared influence approach of Epstein (2001). The analyzed corpus, drawn from semi structured interviews with school stakeholders (n = 11), community members (n = 10) and immigrant families (n = 6), identified two essential dimensions to be considered the leadership and the childishness. This word indicates the need to consider the immigrant student's experience and needs in the dimension of collaboration. On the one hand, our analyses highlight specific practices, such as communication between all stakeholders. But, on the other hand, the absence of other practices such as the decision-making of immigrant families. Therefore, our results support the need for more resources and investments from all levels, especially the government. - The third specific objective aims to compare the EFIC collaboration practices according to the school and social actors who answered a questionnaire (12 school actors, 24 community members and 19 immigrant families). This goal is the subject of an article published by the Canadian Journal of Educational Administration and Policy. The six dimensions of Epstein's (2001) shared influence model form the theoretical framework for this quantitative study. At the end of this research, on the one hand, the analyzes of Kruskall Wallis showed a significant difference between the three groups of actors in terms of decision-making and learning practices at home. However, on the other hand, correlation analyzes have shown that 1) the number of years of experience of school actors in school is positively correlated with the variables communication, volunteering, parenthood and decision-making and that 2) the level class of the young is positively correlated with the parenthood variable. Finally, a practical booklet, named École-familles immigrantes-communauté : outils de collaboration en 42 pratiques et 255 actions clés, published by the Presses de l'Université Laval, is written to make the EFIC collaborative practices available. The writings and testimonies of various educational and social actors through the semi structured interviews conducted in this thesis (sample of article 2) are the basis of its production. First, the booklet exposes, among other things, some myths of the ÉFIC collaboration, its levers and brakes, and various means of communication, making it possible to facilitate the exchange between the actors. Second, the booklet suggests 44 effective practices and 255 actions intended for each of the actors concerned: school actors, the immigrant family, and community members.