The study set out to investigate the impact of interactive whiteboards (IWBs) on teacher--pupil interaction at Key Stage 2 in the teaching of literacy and numeracy. As part of the National Literacy and Numeracy Strategies, IWBs have been made widely available as a pedagogic tool for promoting interactive whole class teaching. In order to investigate their impact, the project looked specifically at the interactive styles used by a national sample of primary teachers. A total of 184 lessons were observed over a two year period. Using a computerised observation schedule, teachers were observed in literacy and numeracy lessons, with and without an IWB. The findings suggest that IWBs appear to be having some impact on the discourse moves used in whole class teaching, but this impact is not as extensive as that claimed by the advocates of IWBs. Lessons which used IWBs had a faster pace and less time was spent on group work. The implications of the findings for classroom pedagogy, teachers' professional development and future research priorities are considered. (Contains 4 tables and 2 figures.)