The impact of killing in combat (KIC) on veterans’ long-term psychological health is multifaceted and influenced by deployment contexts. This study compared two samples of Norwegian veterans from combat-oriented (Afghanistan 2001–2011, N = 4,053) and peacekeeping (Lebanon 1978–1998, N = 10,605) missions to examine how personal threats, witnessing death/injury, and KIC uniquely predicted long-term mental health, alcohol use, and quality of life (QoL). In the combat-oriented sample, personal threats and witnessing death/injury predicted negative outcomes, while KIC did not.