Mathematics anxiety can be a debilitating experience, and research shows that elementary-level preservice teachers experience high levels of mathematics anxiety. Current shifts in mathematics education from a procedural focus to a conceptual focus may exacerbate these high anxiety levels. The research reported in this study explored how preservice teachers' levels of mathematics anxiety are associated with their instructional self-efficacy for teaching procedurally- and conceptually-focused mathematics lessons (N=88). The Abbreviated Mathematics Anxiety Scale was employed to measure preservice teachers' overall mathematics anxiety. This instrument included individual subscales: anxiety about learning mathematics and anxiety about being evaluated in mathematics. A researcher-developed survey instrument measured preservice teachers' self-efficacy for teaching mathematics from two different perspectives: (1) procedurally; and (2) conceptually. Multiple regression analyses indicated that preservice teachers' mathematics anxiety and instructional self-efficacy were significantly and negatively correlated. In addition, significant negative correlations were found: (1) between preservice teachers' anxiety levels for learning mathematics and their instructional self-efficacy for teaching mathematics procedurally; and (2) between preservice teachers' anxiety levels for being evaluated in mathematics and their instructional self-efficacy for teaching mathematics conceptually. Finally, preservice teachers who had not completed a mathematics methods course experienced significantly higher levels of mathematics anxiety than those who had completed a mathematics methods course. Implications of this study indicate that mathematics methods courses for teaching elementary students should focus on improving preservice teachers' understanding of mathematical concepts. Prior research has indicated that mathematics methods courses should incorporate manipulatives as a means for connecting an individual's conceptual understanding to mathematical procedures. In addition, mindfulness and counseling sessions should be suggested as ways to decrease preservice teachers' mathematics anxiety. Suggestions for future research include exploring the impacts of preservice teachers' mathematics content achievement on their mathematics anxiety and instructional self-efficacy. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]