An interactive whiteboard (IWB) is a relatively new tool that provides interesting affordances in the classroom environment, such as multiple visualization and multimedia presentation and ability for movement and animation. These affordances make IWBs an innovative tool with high potential for mathematics instructional environments. IWBs can be used to focus on the development of specific mathematical concepts and to improve mathematical knowledge and understanding. The aim of this paper is to review the existing literature upon the use of interactive whiteboards (IWBs) in mathematics classrooms. The reviewed studies offer a wide view of IWBs' affordances, of the more interesting didactic practices, and of the difficulties of embedding this new technology in the classroom. The capabilities of IWBs to enhance the quality of interaction, and, consequently, to improve conceptual mathematical understanding are broadly recognized. Despite these capabilities, evidence from the studies points to a certain inertia on the part of many teachers to do anything else than use IWBs as large-scale visual blackboards or presentation tools. The emerging view of how to attempt to overcome these obstacles is that there is need for greater attention to the pedagogy associated with IWB use and, more specifically, to stimulate the design of new kinds of learning environments.