As a middle school principal, the author discusses the conditions necessary for incorporating prevention initiatives into students’ lives. This includes, in particular, leadership from the administration, support from the entire staff, a collective reflection by the educational team on the favorable conditions to be created and the methods to be used, as well as taking into account adolescents’ expectations regarding the school system (relationship to knowledge, supportive relationships, recognition of the individual). The values of mediation, expression, and empowerment must be fostered to ensure greater acceptance of messages from adults. The author draws conclusions regarding an approach to substance abuse prevention that could be effective in this context.