This study examined relations between effortful control, parent–adolescent conflict, and teacher–student relationships and the concurrent and longitudinal impact of these factors on adolescent depression and misconduct. In particular, we examined whether the risks of low effortful control and parent–adolescent conflict could be buffered by positive teacher–student relationships characterized by warmth and trust. Data were collected on 1,400 urban youths (52% female, 51% Black, 44% White) who reported on their effortful control at age 13 years and on their depressive symptoms and misconduct from ages 13–18. Teacher–student relationship data were collected from teacher-report at age 13 and parent–adolescent conflict data from parent-report at age 13. As hypothesized, regardless of gender, both early poor effortful control and conflictive parent–adolescent relationship were general risks for adolescents' depression and misconduct. Positive teacher–student relationships protected adolescents against depression and misconduct throughout ages 13–18. In addition, positive teacher–student relationships moderated the negative influences of adolescents' early poor effortful control and conflictive parent–adolescent relationships on misconduct and helped such at-risk adolescents to attain less behaviorally delinquent developmental trajectories over time.