This paper investigates the types of talk moves used by teachers and students following the implementation of a dialogic teaching professional development program. It draws on talk data derived from 42 video-recorded primary English lessons collected as part of a larger impact evaluation of the intervention. The video recordings were subjected to a systematic analysis and quantification of teacher and student talk moves together with a more nuanced, micro-level analysis of a sub-sample of 18 lesson transcripts. The findings showed that teachers in the intervention compared to the control schools made significantly greater use of discussion and dialogue, characterised by open/authentic initiation questions and follow-up talk moves that resulted in students participating more in the whole-class talk and elaborating on their thinking and that of other students. Implications of the findings for classroom practice and teacher professional development are discussed.