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. (Contains 3 figures and 3 tables.)