This research brief focuses on moral injury (MI) among formerly armed actors (FAAs), the cognitive and emotional response that may occur in a person who has witnessed, perpetrated, or failed to prevent acts that go against their moral or ethical beliefs. Unlike post-traumatic stress disorder (PTSD), MI is not widely recognised as a distinct clinical condition, yet it poses significant obstacles to the mental well-being and successful (re)integration of FAAs. The brief explores how morally injurious events challenge healthy self-perceptions and clash with societal expectations, leading to a severe cognitive dissonance in affected FAAs. It examines the impact of MI on military veterans and non-state armed actors, and highlights its potential psychological consequences such as social withdrawal, substance abuse, depression and violent behaviour. The research brief argues that MI deserves attention in psychosocial counseling within (re)integration programs for FAAs. It thus proposes a framework for integrating moral repair into existing FAA mental health treatment programmes, recognising the importance of addressing chronic and intrusive feelings of shame, guilt, and remorse resulting from MI.