This study examines the reasons for using or not using interactive whiteboards (IWBs) by elementary school mathematics and science teachers in Taiwan. It also considers whether there were any significant differences in the reasons according to teaching subjects, teacher gender, and teaching experience. The survey was developed based on an overview of the discussions from prior research related to the benefits and drawbacks in using IWBs. Percentages were high on all six reasons for using IWBs. Of the five reasons for not using IWBs, budget constraints appeared to be the most important reason why the teachers did not use IWBs in their classroom. Male teachers using IWBs showed significantly higher ratings than female teachers for getting students' attention and increasing interaction. Experienced teachers' ratings were significantly higher than novice teachers for getting students' attention, helping teachers explain complex and abstract concepts, and helping the teaching process. In the group of teachers who reported not using IWBs, male teachers showed significantly higher ratings for the lack of time to design teaching materials, and limited sources of related teaching software. Research implications of this study are provided along with suggestions for future study. (Contains 5 tables.)