Health is not just a biological matter (in the sense of the absence of illness) but also a social phenomenon, since it incorporates the quality of relations individuals have with each other and with their environment. The importance of mental health, its interdependence on physical health and the burden that mental disorders cause on a personal, family and social level have gained increasing recognition both by the relevant policymakers and by the general public.Mental health is defined as the state of emotional well-being which prompts individuals to recognise their skills, to effectively deal with stressful life situations, to work to produce results and to contribute to the society in which they live. In our times, man appears to be particularly vulnerable in terms of mental health, and the frequency with which mental disorders are appearing is constantly on the rise. Both promoting health and preventing illness seek to ensure the common goal of maintaining and improving health.Late diagnosis of mental problems in the young can very likely lead to serious mental illnesses in adult life with long-term effects. The World Health Organisation (WHO) has highlighted the importance of promoting mental health and prevention in children and adolescents and urges governments worldwide to include mental health as a key part of their primary healthcare. However, there is nonetheless an immense gap between needs and resource availability. However, in all European Union countries, there is some activity in terms of mental health prevention and promotion. The availability of the practices, resources and infrastructure which has been developed varies from country to country reflecting different situations in healthcare systems, political history and traditions and their understanding of both mental and public health.A literature review highlights examples of best practices and evaluation of the effectiveness of measures to promote mental health among individuals of school age, since it recognises that education contributes to the prevention of the onset of mental illnesses.The programme to promote mental health in children and adolescents in selected areas of Greece ran for the period 2011–2013. It was financed by the Stavros Niarchos Foundation and implemented by the Association for Regional Development and Mental Health on the islands of the NE and Western Cyclades. The measure sought to ensure primary protection of the mental health of children and adolescents. It included awareness-raising and counselling groups for parents of children in each age group, awareness-raising and counselling groups for adolescents about mental health issues and awareness-raising and support groups for teachers in preschool, primary and secondary education.The awareness-raising groups performed an educational support role. The principles of assertive-experiential learning were chosen for the methodological approach. The results were particularly encouraging in all sectors of intervention. The chapter highlights the epistemological and social need for holistic interventions on interactive local systems, to ensure the best outcome of programmes to promote mental health.