Pharmaceuticals are natural or synthetic compounds, which have an impact on the health of humans and animals. The pharmaceuticals in wastewaters originate from human and animal excretions. Pharmaceuticals in the environment are a danger to health and ecosystem balance. The female sex hormone 17β-estradiol can be commonly found in water systems due to widespread consumption of estradiol containing pharmaceuticals and is present naturally in human and livestock excretions. 17β-estradiol increases cancer occurrence and has a negative impact on reproductive health. Therefore, research and application of efficient treatment processes are important in order to develop methods of removal and prevention of water body contamination. In this work, photodegradation of 17β-estradiol in aqueous medium was carried out under ultraviolet irradiation. The experiments were performed in a batch photoreactor, cooled by a water jacket, by means of two monochromatic light sources: UVC (254 nm) and UVA (365 nm). The rate of 17β-estradiol photodegradation was monitored by HPLC. The values of the molar absorption coefficient and the quantum yield as crucial process parameters, which affect the efficiency of the photodegradation, were determined. Under UVA degradation 17β-estradiol does not undergo photodegradation. UVC photolysis has shown to be a very efficient process for 17β-estradiol photodegradation in aqueous medium. After 45 minutes of conducting UVC photolysis 97% of 17β-estradiol has been degraded. The molar absorption coefficient of 17β-estradiol at 254 nm is equal to 872.7 L cm-1 mol-1 while the quantum yield is equal to 0.1068 mol Ein-1. The photocatalytic degradation of 17β-estradiol in aqueous media follows pseudo-first order kinetics with the reaction constant being 0.0715 min-1.