Professional development is a critical part of implementing new instructional strategies. Despite its importance, little information is available explaining if and how professional development motivates teachers' instruction. This qualitative descriptive study examined what influences teachers' motivation to implement STEM instructional strategies. The study interviewed 14 kindergarten through fifth grade teachers who provided information regarding their STEM professional development experiences. The teachers explained how STEM professional development motivated their implementation of STEM instructional strategies. This study determined if STEM professional development had an influence on teachers' motivation to implement STEM instructional strategies. The 14 teachers gave examples of what elements of professional development had the greatest and least influence on their implementation of STEM instructional strategies. The teachers' interviews provided suggestions on STEM professional development motivators to implement STEM instructional strategies. The researcher provided implications for professional development creators and school leaders. Lastly, the researcher included how this study connects to school improvement. [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://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]