Instructional communication behaviors have been routinely associated with student learning outcomes for the past 40 years; however, the explanations for why these relationships exist remain somewhat controversial. Specifically, the relationship between immediacy and learning outcomes continues to be disputed. This study used Self-Determination Theory to evaluate the utility of students’ need for relatedness and their intrinsic motivation to learn as sequential mediators of the teacher immediacy-student learning relationships. Results of a structural equation model supported the theory’s hypothesis, as relatedness and intrinsic motivation to learn operated in serial to mediate the immediacy-learning relationship. These results indicate Self-Determination Theory is a well-suited framework for explaining the relationship between instructors’ communicative behaviors (e.g., immediacy) and their effects on student outcomes.