Relevance. Participation in hostilities is a stressful factor affecting the formation of mental disorders in combatants. According to scarce studies, combatants resigned from the security forces have some problems with mental health.Intention. Catamnestic analysis of mental disorders over time in combatants entitled to retirement pension upon their dismissal from the Internal Affairs bodies of Russia.Methodology. A catamnestic survey was conducted in 209 employees of the Ministry of Internal Affairs of Russia in the Kirov region who were retired from 2015 to 2019. Depending on participation in hostilities, the respondents were divided into two groups: main group, 106 retired combatants from the Ministry of Internal Affairs of Russia, and the comparison group, 103 retired persons without combat experience. Catamnestic, clinical and experimental psychological research methods were used. Statistical processing of the results was carried out using the STATISTICA 10.0. Mental disorders rates were calculated per 1000 military. Significant differences between the two groups were determined using Pearson’s χ2 and the Student’s t-test.Results and Discussion. According to the study results, the military personnel from the main group had statistically significantly more mental disorders (p < 0.001), as follows: organic, including symptomatic mental disorders (F00–F09 according to ICD-10), neurotic, associated with stress, and somatoform disorders (F40-F48). At the time of dismissal from service, military personnel from the main group had higher rates of all mental disorders (p < 0.001), i.e. organic ones, including symptomatic mental disorders. During the period of service, the groups demonstrated a significant increase in organic, including symptomatic mental disorders, mental and behavioral disorders associated with the use of psychoactive substances (F10–F19), and a decrease in neurotic stress-related and somatoform disorders. In the main group of pensioners of the Ministry of Internal Affairs of Russia, this dynamics is more pronounced. Therefore, there are shortcomings in the treatment of mental disorders during the period of service in the Ministry of Internal Affairs of Russia.Conclusion. In order to improve the quality of psychiatric care for combatants from the Ministry of Internal Affairs of Russia, it is necessary to improve approaches to providing psychiatric care in the structure of departmental multidisciplinary healthcare institutions with amendments to the current procedure for therapy and medical and psychological rehabilitation when returning employees from combat zones.