Although numerous organizations have been recommending for several years that health-related actions be based on evidence, the use of scientific research findings by practitioners appears to be problematic in the field of mental health in France. Drawing on research in the field of health knowledge transfer and an analysis of a prototypical situation, this article aims to examine the role of scientific evidence in mental health practice in France. A typology of modes of knowledge transfer and use presents the conceptual model (which includes the “disinterested” mode and the “insight” mode), the instrumental model (which includes the “expert” mode and the “problem-solving” mode), the “strategic” model, and the “interactive” model. Various obstacles to the transfer process identified in the literature are then outlined: problems associated with research questions and findings, those related to dissemination, and those linked to the interaction of different organizational cultures. An analysis of a knowledge transfer situation in mental health in France then helps characterize the French challenges in this field: a lack of understanding of scientific knowledge and methods; confusion regarding the roles and positions of practitioners and scientists; a relationship between the practice and scientific communities built on opposition and a lack of exchange; and a problem in articulating scientific knowledge with the world of practice. Finally, based on data from the literature, several solutions are presented to foster the emergence of constructive cooperation between the scientific and practical communities.[author’s abstract]