Designing and implementing effective preventive interventions in mental health is seen as a responsibility of primary health care, mental health services, public health services and health promotion agencies. Several of these health sectors could be further differentiated according to their primary target populations, e.g. infants, children, adolescents, adults and the elderly. Together, they represent a wide spectrum of agencies. They are challenged to build coalitions in order to develop the common policies and the critical mass needed to needed to have a significant impact on the health of local populations. In addition to the health sector, organizations in many other sectors have activities that aim to promote mental health or are capable of doing so, as they have some control on determinants of mental health and mental disorders. Building strong coalitions across organizations and sectors is a major condition for improving the living conditions and competencies of people to enhance and protect their mental health. Building successful and sustainable coalitions for prevention of mental disorders and mental health promotion requires specific skills and insight to reinforce productive and sustainable collaboration.  For instance, it requires strategies and methods for mental health impact assessment, advocacy, community network analysis and network development. Above all, it requires insight into how mental health benefits are related to the non-health benefits that might be the primary concern of partner organizations whose support we urgently need (e.g. schools, workplaces, local governments, justice). This special plenary and related presentations aim to offer more insight into such strategies and methods and their outcomes, in order to help conference participants in building strong coalitions in their own communities and countries.