The thesis Evaluation of flood control ecosystem service from the upper stream of the Rimavica river to the village Utekáč deals with the modelling of the floodplain in the allocated catchment basin of the Rimavica river, which flows through the village Utekáč, the area with issues with flash floods after heavy rains. We modelled the floodplain by simulating artificial flood conditions in the HEC-RAS and HEC-GeoRAS models. The result of the thesis is focused on the evaluation of flood control ecosystem services and the quantifications of the evaluations in the assessed area. At the beginning, it was important to get acquainted with the issue of ecosystem services, the factors influencing the course of the flash floods and the modelling systems - what principle they work on, how to work with them, or what the alternative software options are. In this thesis, we compared the ability of ecosystems to reduce runoff, based on the values of CN curves. We determined the price of the flood control ecosystem service based on a combination of several factors, which are: the rate of the sub-basin outflow from the total outflow, the value of houses and the value of the ecosystem type.