In a 2010 survey, superintendents in Massachusetts identified proficiency in math as an essential element of college and career readiness for contemporary students (Rennie Center, 2010). U.S. students fail math more often than any other subject, and as a result many students dropout of school, especially low-income and minority students (Schmoker, 2011). Many other students graduate from high school and enter the workforce but do not possess the skills and competencies they need to do well (Rennie Center, 2010). Empowering students to understand and apply math has become crucial to their future success (Telese, 2008), but traditional teacher-centered methods rarely foster the deep and meaningful application of content and skills that is necessary for success (Yetkiner, Anderoglu, & Capraro, 2008). Research suggests that a project-based learning (PBL) instructional approach can motivate students to stay in school and learn math deeply and well (Larmer, Mergendoller, & Boss, 2015) by providing an environment in which students learn to think critically and creatively, collaborate with their peers and teachers, communicate about their learning, defend their efforts to an authentic audience, and persevere in the face of difficulty (Boss, 2015). "The Massachusetts Curriculum Framework for Mathematics" communicates high expectations for student achievement and teacher practices (MA DESE, 2017). The performance-based nature of these expectations has prompted teachers and administrators to revisit the potential of PBL to inspire high levels of student growth and achievement (Larmer et al., 2015). The purpose of this qualitative research study was to explore teachers' perceptions of the use of project-based learning to support middle school math instruction. [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.]