Abstract. Security problems of ancient Rome. The purpose of this study is to show the similarities, and even the continuity of some of today’s security problems in big cities, and ways to overcome them, beginning from ancient Rome. The Romans saw a number of problems with internal security and tried to solve them both from the legal point of view and systematical one. Thus, the authorities responsible for ensuring the safety and responding to specific threats arose. The biggest problem of the security system of ancient Rome was supplying water to the city and to discharging liquid waste. Thanks to the large responsibility of the authorities, first in the Republican period, later in the Principate, the city of Rome could feel safe.