Higher education institutions worldwide now consider Education for Sustainable Development a cross-cutting issue, with the development of competencies to promote sustainable development and global citizenship stated as one of their educational objectives. To explore how this can be implemented in language teaching and learning, the case study teaching method was used in two Swedish language courses in Germany conserning renewable energy and Indigenous peoples’ rights in the Sámi homelands. The study sought to determine whether and in what way the course had altered the students’ conceptions of sustainability. Another aim was to explore the extent to which deeper reflection and transformative learning could be identified as a consequence of the course. Data were obtained from student questionnaires and end-of-course reflective writings. The respondents appeared to have a reasonable understanding of sustainability concepts but acknowledged that their knowledge was relatively general and expressed a desire to learn more. They also reported having gained a more nuanced understanding of the complexity of sustainability issues. However, a deeper level of reflection was evident only in a minority of students. Overall, the results illustrate the necessity and students’ desire to address sustainability issues and the need for training in reflection to facilitate transformative learning.