Context: meso level organizations are intended to link different actors to organize care for a defined population. They act between the macro level of care policies and the micro level of interaction with the patient. The establishment of Territorial Professionnal Health Communities (CPTS) in France is an opportunity for health professionals to participate in structuring primary care (PC) delivery. Objective: to query the Belgian health system to identify meso level organizations and describe them by completing data with a documentary search. Method: qualitative descriptive study conducted by semi-structured videoconference interviews with Belgian professionals considered as experts. The interview guide covered 4 clinical vignettes and 6 PC themes. Data were analyzed and discussed collectively within the research group. Results: 7 interviews were conducted. 5 main organizations illustrate the two “meso-clinical” and “meso-organizational” levels of the meso level. The Circle of General Practitioners (GPs) represent the GPs of a geographical area to organize out of hours care, health promotion, multidisciplinary collaboration, partnerships with hospitals, meeting with local politics. The reform of the Flemish front-line areas offer support to professionals and gives them a responsibility towards the population. Conclusion: the projects of CPTS could be based on some experiences led in Belgium. ; Contexte : les organisations de niveau meso sont destinées à mettre en lien différents acteurs afin d’organiser les soins pour une population définie. Elles se situent entre le niveau macro des politiques de santé et le niveau micro d’interaction avec le patient. L’instauration des Communautés Professionnelles Territoriales de Santé (CPTS) en France est l’occasion pour les professionnels de santé de participer à la structuration de l’offre en soins primaires (SP). Objectif : interroger le système de santé belge pour identifier des organisations de niveau meso et les décrire en complétant les données par une recherche ...