Inquiry-based Learning (IBL) has been considered an essential element of science education for several years. Nevertheless, teachers rarely implement IBL in their own classes. To counter this, professional development (PD) programmes need to examine teachers’ reservations. In this study, we supported five teams of science and technology teachers in developing and realising IBL units for their own classes. To investigate teachers’ beliefs about and dispositions towards IBL, we conducted group discussions at the beginning and the end of this programme. Applying qualitative content analysis, we could identify substantial changes regarding learning environments, goals and scaffolding for IBL.