International audience ; Our paper focuses on the relationship between the diversity of staff and the diversity of users in the hospital environment. We will show the strength of the diversity of staff for customers and beneficiaries, from the experience of a public hospital in Belgium, confronted with the cultural diversity of its audience.The diversity of patients, in languages but also in culture, poses significant problems in providing diagnoses and accompanying patients throughout the illness and the care process. Proposing intercultural mediators is part of the quest for greater efficiency (better satisfying customers and users) and efficiency (making better use of available resources), but also in the interests of equality and social inclusion. This article aims to describe the different components of this job, to better understand the skills required of staff, to show the entire process of internal recognition and to identify the difficulties and debates around the function. It was built in a process of research-action built with professionals involved in mediation, with whom we realized a joint writing work from their field experiences and a process of support of the service of mediated for more than 15 years. ; Notre article porte sur l’articulation entre la diversité du personnel et la diversité des usagers dans le milieu hospitalier. Nous allons montrer l’atout de la diversité du personnel pour les clients et bénéficiaires, à partir de l’expérience d’un hôpital public en Belgique, confrontés à la diversité culturelle de son public. La diversité des patients, notamment dans les langues parlées et maîtrisées, pose d’importants problèmes pour assurer les diagnostics et accompagner les patients tout au long de la maladie et du processus de soins. Y répondre, en proposant des médiateurs et médiatrices interculturels, s’inscrit dans la recherche de plus d’efficacité (mieux satisfaire la clientèle et les usagers) et d’efficience (mieux utiliser les ressources disponibles) mais aussi dans des préoccupations ...