School nurses in France’s Éducation nationale are a specific community within the education sector, entrusted with the mission of education and health promotion, thus requiring an adaptation of their role, their status, and their professional practices. The literature emphasizes the link between knowledge, systems of social representation, and standards of practices that revolve around individual conceptions. Based on a mixed methodology, the study focuses on the analysis of the results of a qualitative study through interviews with a sample of the population, followed by a national survey using questionnaires. These conceptions are strongly influenced by professional practice in the Éducation nationale. The role of school nurses in health education evolves according to the duration of professional practice: from health concepts that need to be taught, to a holistic approach to health education, through to advice and support to schools and teachers. This study advances lines of thought in the organization of initial or in-service training, with the aim of constructing the specific role of the school nurse as “a specialized practice in professional nursing.”