This paper discusses the findings of a case study conducted with an English as a Foreign Language (EFL) teacher at a German secondary school. This case study is part of a research project that investigates the new competencies that EFL teachers need to acquire in order to be able to use the interactive whiteboard (IWB) to develop their practice, informed by a socio-cognitive approach to computer-assisted language learning. The findings point towards various competencies developed by the teacher as she integrated the technology into her teaching, namely: (a) the ability to design IWB-based materials which support opportunities for learner interaction with the whiteboard and with the learning content; (b) the appropriate management of interaction around IWBs in a way that ensures all learners are provided with opportunities to become actively involved; and (c) the ability to find the "right balance" of technology use. (Contains 2 figures.)