Interview data was collected from 299 regular psychostimulant and/or opioid users. Conduct disorder significantly increased the lifetime and past 12 month risk of violent victimization and offending. While CD did not independently predict recent violent victimization, it did predict recent violent offending. Greater alcohol dependence and involvement in drug dealing were predictors of both recent victimization and offending. The study indicates that there is significant temporal stability between childhood CD behaviors and later violent behavior among individuals with substance use problems. The study also highlights that there is heterogeneity in the risk of violence exposure in drug using populations, a finding which has implications for early intervention and for treatment interventions among dependent drug user populations. (Published Abstract)