Relevance of the article - security has always been one of the priority issues of state policy, and considering the fact that the defense forces are an inseparable part of state security, the study of their information security is essential. The feasibility of this study is confirmed by the fact that in the current conditions of development of the information society, the information technology of the Ukrainian defence forces must adapt to the current challenges and threats, to ensure proper protection of information of strategic importance to the state and collected, consolidated and stored by the defence forces. The purpose of this article is to identify problems of information security of defence forces in Ukraine, to find ways of their elimination. Formal logical, systemic structural, comparative and legal methods were used to conduct the research. It is stated that by dividing the information space and cyber space, the legislator has laid down legal regulation of protection of the information space of the state. It is understood that the Lithuanian and Latvian forces for combating threats to the information space were consolidated within the structure of the Ministry of Defence.