This qualitative study explored how secondary mathematics lesson planning, classroom use, assessment methods, and student learning pedagogy and practice changed over a period of three years due to interactive whiteboard (IWB) use. Two active and two future IWB users were individually interviewed each year. Findings indicate that IWBs became increasingly vital to pedagogy, lesson planning became easier, and perceived value to student learning grew more positive for active users. Future IWB users’ perceptions of the positive and negative effects remained consistent throughout the study. Implications for mathematics teacher professional development and how teachers perceive IWB-based instruction will be discussed.