The public supply of adult education is very different between countries, making it likely that there is scope for efficiency gains. The contribution of this paper is to provide an economic evaluation of the earnings impact of adult education at upper secondary level (AE) in Sweden, where the supply is plausibly larger than in any other country. The analysis is based on register data for 1990-2002 of the cohort born in 1970 on accomplished AE course credits and possibly subsequent higher education. Difference-in-differences estimates indicate that for AE enrolees in 1994-1996, a year of AE credits increased earnings in 2002 by 6% for males and by 4.5% for females. The estimates are reconciled with conflicting results from earlier studies. According to crude calculations, which disregard other societal benefits of AE, the earnings benefits are sufficient to cover the costs incurred by society within 17 years. (Contains 6 tables, 3 figures, and 9 notes.)