Mental health of employees is an emerging concern for societies and employers in the Baltic Sea Region. Even before the pandemic and the war in Ukraine, half of EU workers considered stress to be common in their workplace, and stress contributed to around half of all lost working days. Combined with an already prevailing lack of qualified work force, this puts the ability of enterprises (including public organisations) to withstand existing and future crises in jeopardy. In short: to be economically resilient, companies and societies need a mentally resilient work force. Protecting workers and preserving their work ability is the objective of Occupational Safety and Health (OSH). In the past, however, OSH legislation, standards and education have mainly focused on physical hazards and accident prevention and not paid enough attention to psychosocial risk assessment, health promotion and prevention measures. The Mental Health Matters project wants to change this and will bring together policy makers, employer and employee representatives, practitioners, researchers and educators in the field of OSH. They will assess the adequacy of policies and practices and propose measures to better prepare OSH systems and OSH professionals to deal with current and emerging psychosocial risks. Moreover, the project will develop a “first-aid kit” to support owners and managers of SMEs that do not have access to OSH professionals in assessing psychosocial risks and taking preventive action.