In order to create the best possible prerequisites for mental health and wellbeing in the Nordic population, increased emphasis is warranted on both family and work wellbeing and related contextual mechanisms and interactional factors across these key setting in everyday life. PLEX-WELL contributes to the knowledge-base on multi-level family well-being determinants in the Nordic setting, with a particular focus placed on work-life balance – and special attention paid to issues of gender inequalities. The overarching aim of the project is to systematically examine the complex mechanisms of mental wellbeing in families in the Ostrobothnia region and the Nordic context alike, identifying various multi-contextual support and risk factors and their interactions. Further, the project aims to generate an integrated roadmap of mental wellbeing research targeting families in a Nordic context, where the importance of simultaneously studying the work and family context and related risk and support factors for mental wellbeing are highlighted.