The emergence of plural societies is part of an irreversible historical and cultural movement. It is expressed in particular by the increasing mobility of people, knowledge, practices and techniques. Whether it be political, social, economic, cultural, religious or sexual, diversity therefore appears to be a requirement with which the balance of democracy, the challenges of civil society, public policies and professional practices must now be met. This creates new health challenges and poses new challenges, notably in the area of mental health. Thus, a relativist vision limited to respect for cultural differences gradually replaces a new paradigm advocating an intercultural or transcultural approach. It focuses more on life trajectories, dynamic processes, interactions and the development of clinical devices in the direction of opening the therapeutic space to confrontation, mediation and misuse aspects. With this in mind, diversity, as well as the related concepts of culture, identity and hybridisation, are embodied and developed within the clinical meeting itself, from which new positions emerge. The aim is to overcome the focus on cultural differences, a concept which often underpins differences and creates a sense of inanchable gap between people of different cultures. Conversely, grasping the changes under way and recognising the diversity that characterises our contemporary societies makes it possible to take into account, in the field of observation and analysis, the range of our own actors and arrangements. Some avenues for reflection and analysis are thus outlined in order to elucidate the various registers that build and condition the understanding and use of the concept of diversity in the field of mental health. The aim is to identify less the relationship between health and migration than the context in which researchers and practitioners in the field of mental health understand diversity and renew their own professional culture.