The practice of countering the illegal paramilitary groups shows that one of the issues is still the organization of the cooperation between the force structures of the state. In this context, there is a need for a permanent organization of close cooperation during peacetime, crisis and war among the state bodies, such as Ministry of Internal Affairs, Intelligence and Security Service, Commands of the National Army, Prosecutor’s Office, etc. on the following matters: missions, directions, forms of activity, place and time of actions. The experience of the recent military conflicts and the measures taken to improve the cooperation among the force structures of the state demonstrates that the problem of cooperation, quite current and complicated, will be solved only with joint efforts of the commanders and headquarters of the state’s force structures, involved in countering illegal paramilitary formations.