There is increasing interest in research-based education in the Western World as it is assumed to strengthen school improvement capacity. Previous research shows that school principals play a pivotal role in realising such vision. The aim of this article is to explore the influence of principals on research-based education in their local municipal adult education (MAE) institutions. The study is informed by the theory of practice architecture. Data rely on 10 interviews with the principals of eight local MAE institutions. The study draws attention to how inherent contradictions in the national education system may hinder the policy ambitions related to research-based adult education. These contradictions not only affect principals' leadership practices in various ways, but also their ability to ensure research-based adult education. It is suggested that understanding the practice architecture is fundamental to enhancing leadership practice, which is also exemplified.