Micropollutants have become a significant global problem in recent years. Traces of human activity are visible in every segment of the environment, especially in aquatic ecosystems. Through the continuous development of industry, population growth, irresponsible waste disposal and excessive use of pesticides, micro-pollutants are released into the environment where they accumulate and negatively affect the environment and the health of living organisms. There are various wastewater treatment techniques that involve a combination of physical, chemical and biological methods; however, they are not fully applicable to micropollutants due to a particle size and extremely small amounts of micropollutants in the environment. In Croatia, micropollutants are monitored according to the Watch List of contaminants of emerging concern (CECs). The aim of this study is to analyze samples of the Plitvice River to determine the presence of micropollutants such as pharmaceuticals, pesticides and microplastics. The method used to test the samples from the Plitvice River in this paper is mass spectrometry and liquid chromatography on an Agilent 6350 Q-TOF LC / MS device.