This mixed-methods research study explores the potential relationship between the teacher self-efficacy and pedagogical conceptual change. The study context was a drama-based instruction professional development model that specifically sought to facilitate pedagogical conceptual change. Significant differences were present between elementary and secondary teachers in self-efficacy for teaching and in pedagogical conceptual change. However, self-efficacy did not predict conceptual change. The independent variable (elementary and secondary teachers) was a significant moderator between years teaching experience and self-efficacy. We discuss the significance of these findings in light of teacher training and teacher effectiveness. (Contains 6 tables and 3 figures.)