This research examined the hypothesis that the association between parental involvement and adolescents' school adjustment is in part channeled through adolescents' development of positive teacher-student relationships. Three times over the course of 18 months, adolescents (N = 383; mean age at the first wave of the study = 12.31) completed surveys about their parents' involvement in their learning, the quality of their relationships with teachers, and aspects of their school adjustment, including their valuing of school, school engagement, and perceptions of competence. Parental involvement was associated with positive teacher-student relationships six months later, even when adolescents' prior relationships with their teachers were taken into account. Positive relationships between teachers and students were in turn associated with core dimensions of adolescents' subsequent school functioning, above and beyond their prior school functioning. Teacher-student relationships in part explained the longitudinal association between parental involvement and adolescents' school functioning. (PsycINFO Database Record (c) 2019 APA, all rights reserved).