Although school principals are primarily held accountable for student achievement, they have only an indirect impact on that achievement (Darling-Hammond & Bransford, 2007; Hallinger & Heck, 1996; Supovitz, Sirinides, & May, 2010). Teachers affect student achievement directly, and principals affect teachers. Because faculty trust in the principal is one variable principal's affect in teachers that could have a positive impact on student achievement (Bryk & Schneider, 2002; Sweetland & Hoy, 2000; Tschannen-Moran, 2001), the challenge for principals is knowing what will impact their teachers' trust in them (Blake & MacNeil, 1998). This study investigated relational trust and its influence on student achievement in mathematics. Research question 1 looked at whether student achievement in mathematics can be predicted based on teacher-principal trust and student demographics. Research question 2 looked to determine if a difference existed in student achievement in mathematics between the means of schools with high and low teacher-principal trust levels. The findings in this study suggests that when trust exists in the relationship between the school principal and teachers, students experience greater achievement levels in mathematics. This study aligns with Bryk and Schneider's Relational Theory of Trust and implies that when high levels of trust exists within the members in a school community, the consequences are positive and quite significant. This study provides implications for school practitioners and leaders as the findings provide a basis for school improvements and closing the achievement gaps within marginalized student. [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.]