The adoption of the Lisbon Strategy in 2000 marked the beginning of a European (adult) education policy defined by common goals, implementation tools and financial resources. Adult education (AE) policy is exercised in the form of "soft law" and supported by various governance mechanisms and policy instruments, such as funding schemes. The study reported on in this article examined the impact of the Erasmus+ programme on the AE system, its organisations, and the professional development of educators and learners participating in mobility exchanges in Slovenia. The study drew on research into European governance in AE. It also used mixed methods to explore the impact of Erasmus+ on AE in Slovenia at micro, meso and macro levels. Quantitative data were collected through a survey completed by 51 AE organisations. Qualitative data were gathered through document analysis of AE policies, five focus group discussions with 23 participants from selected AE organisations, three focus group discussions with 12 adult learners, and four individual interviews with decision makers and project coordinators. The findings point to the important role of Erasmus+ in the professional development of organisations, educators and learners engaged in non-vocational AE, and in supporting social goals and counterbalancing the dominant vocational orientation of European AE policy.