In this study, we address the kind of knowledge that is required for Master’s level nurse education for lifespan mental health promotion and prevention. Data were collected through structured interviews (N = 109). The interviews were conducted across five European countries. The data were analysed using a thematic content analysis approach. The findings show that Master’s level nurse education needs knowledge related to lifespan issues. Needs were raised in several issues like importance of increasing skills and knowledge of mental health workers. We conclude that there is a need to emphasise the knowledge required for mental health promotion and prevention for Master’s level nursing education across Europe.