The pursuit of sustainable development is a necessity for life on Earth and the future of humanity. Education is important in this endeavour; therefore, creating knowledge about teachers’ teaching for sustainable development is essential. This study aimed to investigate how Swedish upper secondary science teachers adjust their teaching of the environmental dimension in sustainable development to the different vocational education programmes their students attend. Data were collected through individual semi-structured interviews with 15 in-service science teachers and analysed by thematic coding. The result showed that most teachers (but not all) adjusted their teaching to the students’ vocational educational programme; however, they did it to different extents and in different ways. The result presents teachers’ descriptions of and arguments for adjusting their teaching linked to the pedagogical content knowledge (PCK) framework. The PCK framework is used as a theoretical lens in this study. Further research is needed to investigate how science teachers’ adjustments to students’ vocational education affect the students’ knowledge of the environmental dimension in sustainable development and how that affects actions in their future professional life. © 2024 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.