For thousands of years it has been known that aggression as a symptom appears in numerous psychiatric disorders and diseases. During the last decade the appearance of the aggressive behavior related to the posttraumatic stress disorder (PTSD) has been frequently investigated, often associated with war trauma. The goal of this study is to analyze the impact of alcoholism on a way war veterans suffering from chronic PTSD express and control aggression. The sample included 240 war veterans with chronic PTSD. The subjects were divided in two groups. PTSD group (n=147) and controlled group composed of those suffering from alcoholism in addition to PTSD (n=93). In this study, the following psychological instruments were used: The Harvard trauma questionnaire for PTSD diagnosis (HTQ); the questionnaire for self-evaluation of aggression (STAXI); The Profile Index Emotion (PIE); questionnaire for auto-diagnosis of alcoholism (CAGE). The obtained results indicate that subjects who have PTSD with co-morbid alcoholism are more deprived, aggressive (p < 0.001) and oppositional (p < 0.05) in comparison to subjects whose PTSD is not combined with alcoholism (PIE). The aggression is statistically more expressed in subjects with PTSD who have also been diagnosed with alcoholism on all subscales in comparison to subjects with PTDS who have not been diagnosed with alcoholism: the current state of aggression, the general state of aggression, aggression towards an unfair treatment, aggression directed inwards and outwards (p < 0.001); aggression towards nonspecific provocation and a general way of expressing aggression (p < 0.05) (STAXI). Subjects that had PTSD combined with alcoholism show a higher degree of aggression in comparison to subjects with PTDS who are not diagnosed with alcoholism.