Mental ill-health accounts for nearly one-quarter of the total burden of ill-health in the European region affecting 27% of adult Europeans in any given year. The cost of mental ill-health accounts for 3-4% of GDP with much of this burden due to lost productivity. There are an estimated 163,000 suicides in the European region annually. The issue of promoting better mental health is therefore pertinent throughout European society as a central economic and quality of life indicator. Mental health promotion is a multidimensional concept that implies the creation of individual, social, and environmental conditions, which enable optimal overall psychological development. Key determinants of mental health and well-being include; personal autonomy; adaptability; ability to cope with stressors; self-confidence; social skills; social responsibility; and tolerance. School environments represent one of the key arenas for the social, personal and emotional development of young people and are potentially the most powerful setting for promoting mental health and well-being. The aim of ‘Happy Days’ is to reduce the immense suffering for individuals, families and communities caused by mental disorders and suicide and to mitigate the pressure placed on health, educational, economic, labour market and social welfare systems across the EU by supporting schools to promote mental health and well-being with appropriate tools and training within a school-based policy context and framework. It will ensure that policies for mental health and well-being can be developed in any school and supported through appropriate teacher induction. Through the provision of a range of innovative text and Internet based resources its objective will be to support and motivate school management and staff to address the issue of positive mental health promotion. The Happy Days Mental Health Policy Tool-kit will comprise a full range of tools, resources and pedagogical supports in all partner languages.