Background/Aim. Consequences of individual adverse childhood experiences for adult mental health have been precisely studied during past decades. The focus of past research was mainly on childhood maltreatment and neglect. The aim of this paper was to determine association between multiple adverse childhood experiences and psychiatric disorders, as well as their correlation to the degree and type of aggressiveness in adult psychiatric patients. Methods. One hundred and thirteen psychiatric outpatients were divided into three diagnostic groups: psychotics, non-psychotics and alcoholics and compared with fourty healthy individuals. Adverse childhood experiences data were gathered retrospectively, using the Adverse childhood experiences questionnaire and explanatory interview. Aggressiveness was assessed using Buss-Perry Aggression Questionnaire. The Student's t test, ANOVA and correlational analysis were used for evaluation of statistical significance of differences among the groups. A value p < 0.05 was considered statistically significant. Results. Our results showed that the mean number of adverse childhood experiences in each group of psychiatric patients, as well as in the whole group of patients, was statistically significantly higher than in the group of healthy individuals (p < 0.001); there was a statistically significant difference in score of physical aggressiveness between the patients exposed to adverse childhood experiences and those who were not exposed to them (p < 0.05); scores of physical aggressiveness were in positive correlation with the number of adverse childhood experiences (p < 0.05). The highest mean score of adverse childhood experiences was evidenced in the group of patients with psychotic disorders. Conclusion. Multiple adverse childhood experiences are significantly associated with psychotic disorders, nonpsychotic disorders and alcohol dependence in adulthood and their presence is important morbidity risk factor for psychiatric disorders. They are in positive correlation with physical aggressiveness of the patients from these diagnostic groups.