This article reviews Education for Sustainability (EfS) in the secondary sector across a range of countries. Drawing on journal articles, book chapters and official reports, it identifies some of the more successful approaches to implementing EfS within the secondary sector. The authors first discuss the importance of educating for sustainability at the secondary level and then explore barriers to effective EfS in secondary schools. They go on to share their insights into contextual factors that influence EfS practices which are reported in the case studies. In particular, they discuss the influence of (a) politics and curriculum renewal, (b) alignment of curriculum, resources and teaching, (c) the perceived state of EfS and (d) teachers' professional development as determinants of EfS implementation and success.