Abstract: This is a qualitative study of the issues which arise for teachers when planning and teaching sustainable development in primary school classrooms. Nine primary teachers participated in a programme of professional development concerned with education for sustainable development, and subsequently planned and taught a topic with a sustainable development focus. The teachers were interviewed at the planning stage, just before teaching and after teaching, using an interview schedule based on a theoretical framework designed by the authors. Seven key issues are identified and discussed in depth, namely: sustainable development and the National Curriculum; choosing a topic; making it sustainable development; 'learned helplessness' and empowerment; personal understanding of sustainable development; the teaching of controversial topics; and teacher time. Three further issues are discussed more briefly (resources, teaching strategies and language). In a final section we consider how the teaching seen in this study compares with conceptions of education for sustainable development found in the literature.