National data on student disengagement show a pervasive trend that currently makes this phenomenon one of the biggest challenges faced by teachers worldwide. Much research on student disengagement examines the problem through an indirect framework in which deficiencies in positive social conditions or psychological states are tested as predictors of disengagement. This study uses a different lens by examining how "negative" student-teacher interactions differentially predict disengagement in adolescent students. Using self-determination theory, this study advances two hypotheses: H1, student perception of psychological need thwarting will have a stronger relationship with student disengagement than student perception of the lack of need support, and H2, the relationship between student perceived psychological need thwarting and student disengagement will be mediated by psychological need frustration. With data from 4694 students, ex post facto study findings confirmed the anticipated increased variance in disengagement when testing negative student-teacher interactions. Further, the hypothesized mediating effect of psychological need frustration was supported.