Objective: Promoting health, and in particular developing psychosocial competences, at school encourages the emancipation of pupils and creates a favourable school environment. Furthermore, by helping to improve academic success, they improve pupils’ overall health. However, school professionals need to be trained to develop students’ psychosocial competences. The aim of this study was to describe the perceptions of French National Education professionals who have attended in-service training in psychosocial competences. Method: This research adopts a mixed methodology. An online questionnaire was administered to 304 professionals in order to measure their levels of satisfaction and professional development following the training. Then, 14 professionals took part in individual semi-structured interviews to discuss their needs and the obstacles and levers they encountered in reinvesting what they had learned into their professional practice. Results: The quantitative data showed that the professionals have an average satisfaction rating ranging from 6.96 to 8.22 out of 10 depending on the variable measured, but that they need to discover more tools and practices to develop psychosocial competences (79.28%). The qualitative data reveal that continuing training enables National Education professionals to exchange ideas with their peers and to review their posture (78.57%). They were able to experiment with psychosocial competences according to their needs and modified their practices as a result of the training (57.14%). Conclusion: This study suggests that continuing training in psychosocial competences leads to changes in the attitudes and practices of National Education professionals, despite significant heterogeneity in terms of the length of training. Future research could focus on the actual practices of professionals trained in the development of psychosocial competences in order to assess the difficulties they encounter.