This study explores the changing manifestations of risk behaviour among secondary school students, with a focus on the growing impact of digital addictions and cyberbullying alongside more familiar patterns such as substance use, aggression, and truancy. These forms of behaviour influence school climate, academic performance, and mental health, making prevention a pressing concern for educators and policymakers. The research draws on a qualitative design that integrates interviews, classroom observation, group discussions, and a case study, analysed through grounded theory and interpretative phenomenological approaches. The findings suggest that preventive strategies are effective only when embedded in the broader culture of the school, supported by trained staff, reinforced through cooperation with families, and linked to external expertise. Particular attention is needed in strengthening media literacy, enhancing psychological resilience, and sustaining preventive work within class groups. The study highlights the importance of systematic evaluation and positions prevention as an essential part of educational policy rather than a set of fragmented initiatives. In doing so, it contributes original insight into the relatively underexplored field of secondary education and offers guidance for more inclusive and responsive approaches to prevention.