Managing classroom discussions that maximise learning through the phases of inquiry in primary science requires a rich repertoire of teacher knowledge and skills. Twelve teachers participated in a professional learning program focussed on building teachers' knowledge, confidence and self-efficacy for managing classroom discourse and using puppets to engage students in discussions. The teachers developed sophisticated understandings about the role of discussion in supporting learning and made significant gains in confidence and self-efficacy for managing classroom discussions. Following the professional learning intervention, the teachers asked more open questions eliciting students' ideas and explanations, increased the proportion of student talk in discussions and the number of elaborated utterances made by students. (Contains 6 tables and 3 figures.)