The purpose of this study was to observe and analyze the use of Interactive Whiteboards (IWBs) by high school mathematics teachers with varying degrees of IWB experience. Six teachers participated in the study, two in each IWB experience category: Beginner, Intermediate, and Experienced. Two lessons by each participant were video-recorded and analyzed according to the guidelines of Glover, Miller, Averis, and Door (2007). Qualitative analyses of the video-recorded lessons indicated that IWB experience does impact usage during lessons. In general, the more experienced IWB users demonstrated greater knowledge about IWB features and how to integrate them into lessons to improve student learning. However, effective collaboration with an Experienced IWB user appeared to improve the performance of a Beginner IWB user compared to other, less experienced IWB users. Collaborations between similarly skilled participants did not seem to have as much of an impact on IWB knowledge.