Background: Identifying deliberate self-harm (DSH) and peer victimization in adolescents is a public health issue. The present study evaluates a three-wave longitudinal model to examine the effect of peer victimization on DSH and the roles of internalizing problems (depression and anxiety) and perceived peer and teacher support climate in this relationship.

Methods: The participants were 2381 adolescents (51.2% boys, Mage = 13.38, SD = .59) from Chinese middle schools. Self-report measures were used to collect data every 6 months in three waves.

Results: (1) Peer victimization at T1 positively predicted DSH at T3. (2) Depression at T2, rather than anxiety, mediated the relationship between peer victimization at T1 and DSH at T3. (3) Perceived peer support climate at T1 played a moderating role between peer victimization at T1 and depression and anxiety at T2, but perceived teacher support climate did not. Peer victimization had a stronger predictive effect on depression and anxiety for students with high level of perceived peer support climate.

Limitations: Study limitations include the short interval (6 months) of the longitudinal design, the reliance on self-report questionnaires, the inclusion of only one aspect of student-student and teacher–student relationships, and the age limitation.

Conclusions: The results demonstrated the importance of prevention for improving social and emotional skills to reduce peer victimization and of interventions to promote a peer support climate in the classroom. The findings highlight the need to consider different types of internalizing problems and perceived support in studies of DSH in adolescents.