This is a qualitative study of the challenges identified by geography student teachers in their learning to teach about education for sustainable development in English secondary schools. The student teachers were participating in a development and research study in the context of an established initial teacher education programme consisting of contributions from school-based and university partners. Data for a cohort of 19 post-graduate student teachers, from open proformas and follow-up interviews, were analysed to identify what the student teachers themselves saw as the challenges. Three main areas of challenge were identified and are discussed in depth, namely challenges related to the complexity of subject matter, to teaching and learning approaches and strategies, and to differences between student teachers' beliefs about education for sustainable development and the context for their teaching. A conclusion draws on the nature of these challenges to suggest appropriate student teacher learning outcomes and activities for consideration by teacher educators. (Contains 1 table.)