Moral injury (MI) is a form of traumatic stress induced by perpetrating actions that transgress a person’s beliefs and values. Existing research on MI has been mostly confined to military veterans, however there is reason to believe that the risk of MI among child soldiers is higher due to their age and history of abduction. This study examined the risk of MI in former child soldiers in Liberia and tested whether age and history of abduction moderate the relationship between perpetrating violence and MI based on a sample of 459 former child soldiers. Results from regression analysis confirmed that perpetrators had a higher risk of MI. However, while younger perpetrators were more vulnerable to MI, abduction history had no statistically significant moderation effect on the risk of MI. Further analysis also revealed that the moderation effects are primarily on anxiety, avoidance and negative feelings but not re-experiencing. These findings suggest that new tests and treatment models may be required for future disarmament, demobilization, rehabilitation and reintegration (DDRR) policy.