The social purposes of education are long term and oriented towards the construction and maintenance of a sustainable future. This article focuses on developing-country contexts with relatively low formal school enrolment rates, where dropout and failure rates are alarming, and where many children leave school semi-literate, soon to relapse into illiteracy. This has negative consequences for their participation as individuals in the creation of a sustainable world. Since the 1960s, nonformal basic education has offered alternative educational and training activities, with innovative learning methods aimed at the development of practical skills, including matters of health, sanitation, literacy, to be applied in real-life situations. Drawing on a five-year empirical study of young people at the point of transition be-tween the nonformal and formal sectors of schooling in Bangladesh, this article analyses the nonformal education paradigm against a framework of models linking education and sustainable development. By following an activist citizen model, nonformal education empowers students to critically consider new circumstances and to believe that they can make a change when needed. (Contains 5 notes and 1 figure.)