This multiple case study sought to examine the individual experiences of three different teachers' experiences with learning about and using project-based learning in their elementary classrooms. The following factors influencing teachers' instructional decision making were used: teacher knowledge, teacher pedagogical beliefs, teacher self-efficacy, and school culture. While individual teachers' experiences differed in terms of the different factors that were more influential than others, teacher pedagogical beliefs were the most critical in influencing teachers' instructional decisions followed by teacher self-efficacy, teacher knowledge, and school culture. Teachers who held constructivist beliefs were able to sustain the use of project-based learning practices in their classrooms even when encountering common barriers. The strength of rural community involvement in PjBL implementations improved both student and teacher experiences. Implications for these findings indicate the need to provide access to professional development programs that provide extensive PjBL knowledge as well as addresses teachers' pedagogical beliefs using models for high-quality professional development. More research is needed to better understand on a broader scale the impacts of teachers' pedagogical beliefs on their sustained use of project-based learning practices. [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.]