An aim of the study was to find symptoms of posttraumatic stress disorder (PTSD) that had an effect on aggressive behavior in combatants and to elaborate rehabilitation measures for such behavior. One hundred and seventy-four veterans, aged 22-43 years who committed criminal actions, were examined. Aggressive criminal behavior was noted in veterans with long-term combat experience, especially in conditions of particular intensity (extreme severity) of combat stress. These people had difficulties in the adaptation to civil life due to the presence of PTSD and characteristic personality changes. In all cases, criminal actions have been committed under an acute stressful situation of different severity associated with the interpersonal conflict (immediately or gradually developed). In these conditions, some PTSD symptoms masked real details of psycho-traumatic conflict situation creating the impression of relentless confrontation.