['It remains unclear whether violent offending among injecting drug users (IDU) is the direct result of drug use factors or whether they are predisposed to violent behaviour from childhood. The current study sought to identify substance use and early-life correlates of lifetime violent offending among IDUs and to determine what risks contributed to recent violent offending.', 'Three hundred community-based regular IDUs were administered a face-to-face cross-sectional structured interview examining correlates of violent offending.', 'One-third (34%) of IDUs had committed violence in the past 12 months, 42% more than 12 months ago and 24% had never been violent. Predispositional and substance use risk profiles were poorer among IDUs who had been violent, but many of these risks were even more prevalent and severe among those who had been violent in the past 12 months. Multinomial logistic regression found that IDUs who had been violent in the past 12 months had greater polysubstance and higher trait aggressive personalities than the other IDUs, whereas they were further differentiated from non-recent violent IDUs in having more involvement in drug dealing and more likely to screen positive for conduct disorder.'] Do the association of early-life and substance use risks to violent offending among injecting drug users?