In recent decades, some governments (e.g. Canada, the UK, Australia) have imposed far-reaching professionalisation processes on national sport federations (NSFs), while others (e.g. Switzerland) have made only minor impositions and relied more on NSFs to self-regulate. As governments must decide on the extent to which sport policy imposes professionalisation processes on NSFs, understanding the challenges and opportunities arising from both policy-imposed and self-regulated professionalisation processes is relevant. However, extant literature has focused mostly on professionalisation processes imposed by sport policy. Therefore, this study aims to analyse the context, action, content and outcome of self-regulated professionalisation processes to identify the challenges and opportunities arising from these processes. A framework of professionalisation and a corresponding processual approach build the conceptual background of this study. A single-case study is applied to enable a holistic and long-term analysis of the proceedings of a Swiss NSF’s professionalisation processes. The results reveal the mechanisms of self-regulated professionalisation processes (i.e. how contexts and actions shape outcome), thus leading to a conceptualisation of these mechanisms and conclusions about challenges and opportunities arising from selfregulated professionalisation processes, which are useful for sport managers and policymakers.