ObjectiveFamily conflict is a risk factor for suicidal behaviors among adolescents. However, few longitudinal studies have investigated this association and explored the mediation effect of behavioral and emotional problems. This study aimed to examine the longitudinal association between family conflict, internalizing and externalizing problems, and suicidal behaviors in a large sample of Chinese adolescents. MethodThis longitudinal study of 7,072 adolescents was based on the Shandong Adolescent Behavior & Health Cohort (SABHC). Participants completed a self-administrated questionnaire to assess family conflict, internalizing and externalizing problems, suicidal behaviors, and family demographics at baseline. Excluding adolescents with any suicidal behavior at baseline (N = 839), others (N = 6,233) were allowed to report their internalizing and externalizing problems and suicidal behaviors one-year later. Path analyses were conducted to examine the mediation relationship of internalizing and externalizing problems between family conflict and suicidal behaviors. ResultsOf 6,233 participants, mean age was 14.52 at baseline and 51.2% were males. Adolescents with subsequent suicidal behaviors reported higher scores in family conflict, internalizing and externalizing problems (Ps < 0.01). Path analyses showed that internalizing and externalizing problems played a significant mediating role in the associations of family conflict with suicidal behaviors after adjusting for covariates. ConclusionsFamily conflict is associated with suicidal behaviors in adolescents, which is partially mediated by internalizing and externalizing problems. Internalizing problems is the major mediator between family conflict and suicidal thought or suicide plan; however, internalizing and externalizing problems play similar mediating roles in the family conflict-suicide attempt link.