This study examines the relationship between violence exposure and early substance use as mediated by trauma symptoms. The Assessment of Liability and Exposure to Substance Use and Antisocial Behavior Scale was used to assess violence exposure at age 10 and substance use by age 12. Mediation analysis indicated direct relationships between violence exposure and tobacco/illegal drug use and indirect relationships between violence exposure and girls' substance use through trauma symptoms. Practitioners should consider violence exposure as a risk factor for early substance use in high-risk youths and potential gender differences in trauma symptom pathways to early substance use.