Adult education is often defined to emphasise cultural and societal development. This paper proposes that the concept should be more inclusive and that vocational education and training for adults has played a bigger role than is usually recognised. This has not been subject to much research and basic facts are often virtually unknown. In this paper, the opportunities for adults in Sweden to participate in vocational education in the period 1918-1968 are explored. The main focus is on vocational schools and the paper demonstrates that they were to an increasing degree being used by adults, rather than the young people they were intended for. Vocational education was an important educational option for adults in Sweden. Since the system for vocational education was similar in most European countries in this period, the results in this paper suggest that vocational education was an important form of adult education also in other countries.