Synthetic hormone 17α-ethinylestradiol (EE2) is one of the main components of oral contraceptives. Entering the aquatic environment EE2 interacts on estrogen receptors of aquqtic organisms. It’s impacting their survival, growth, development and reproduction. Research shows how EE2 affects different trophic levels of aquatic organisms. There were appropriate test organisms used for each trofic level: phytoplankton – Desmodesmus communis, zooplankton – Daphnia magna, zoobenthos - Hyalella azteca. Accute and chronic toxicity tests were carried out. It was found that elevated EE2 concentrations in environment significantly affect their abilities to survive, grow and reproduce. Result of this research show that according to sensitivity against EE2 used test organisms ranges: Desmodesmus communis > Hyalella azteca > Daphnia magna.