The aim of this study was to compare aggressive behavior in soldiers with combat-related post-traumatic stress disorder (PTSD), PTSD comorbid with alcohol addiction and alcohol addiction only. Three groups of male combat experienced soldiers with PTSD (n=43), PTSD comorbid with alcohol addiction (n=41) and alcohol addiction (n=39) were compared by Aggression rating scale A-87. PTSD was diagnosed according to DSM-IV criteria and Watson's PTSD rating scale. Alcohol addiction was diagnosed according to DSM-IV criteria and CAGE Questionnaire. Combat-experienced soldiers with alcohol addiction as well as soldiers with combat-related PTSD comorbid with alcohol addiction have a high level of verbal latent aggression (VLA), (F=26.65; P<0.001), physically latent aggression (PLA), (F=37.86; P<0.001), indirect aggression (INA), (F=56.94; P<0.001), verbal manifest aggression (VMA), (F=18.35; P<0.001), and physically manifest aggression (PMA), (F=43.22; P<0.001), vs. soldiers with combat-related PTSD without comorbid conditions. Alcohol addiction is a severe factor in increasing aggression levels in soldiers with PTSD.