Scaling up educational innovations is a complex endeavour. It often fails or is only successful to a limited extent. More knowledge is therefore needed about the factors that lead to successful scaling up and about the challenges in doing so. The factors fostering the scaling up of educational innovations depend on the level where innovations are expected-at the teachers', schools', regional or at the national level. There is a lack of knowledge about these factors and their interconnectedness, in particular regarding large initiatives aiming at innovations at some or even at all of these levels. This paper reports a meta-study building on several existing empirical studies, theoretical considerations and complementing new studies related to the multi-layered nationwide initiative IMST (Innovations Make Schools Top) in Austria. The meta-study synthesises findings and considerations regarding IMST and aims to analyse and identify relevant fostering factors and challenges. The diffusion of innovation (DOI) theory and the self-determination theory (SDT) are used as lenses on the complex topic of scaling up of educational innovations. The meta-study highlights the particular relevance of the factors need for competence (referring to SDT) as well as relative advantage and trialability (both referring to DOI) in scaling up the initiative. As major challenges, we highlight the interconnection between individual and organisational learning, the balance between a bottom-up and top-down strategy and the need to further build up resources in subject didactics in Austria. Finally, we sketch ideas how to further develop IMST.