Pharmaceuticals, enter the aquatic environments through sewage treatment plants and may affect fish. This examination paper is a literature study that focuses on Selective serotonin reuptake inhibitors, SSRIs, exposure and the impacts on teleosts in the Baltic Sea by assessment of peer-reviewed literature and material. Teleosts affected by exposure of these substances may demonstrate physiologically as well as behavioral alterations. These can be observed as alterations in aggression, boldness, mobility, growth, feeding rate or in endocrine processes. The potential of which SSRI may effect teleosts depends on the pH of the aquatic environment, temperature, other contaminants and the fat solubility of the substances. Some effects caused by SSRI exposure may elicit ecological impacts. These particularly concern changes and effects in terms of evasiveness, reproductive capacity and ability to find food as well as alterations of interspecificity. Even the balance between population density, individual fitness and by extension survival might be affected. Effects in interspecificity may potentially lead to local extinctions and changes in food webs. Furthermore, results demonstrated that when a substance is bioaccumulated and the teleosts are eaten by predators on higher trophic levels, marine ecosystems can also be affected. Moreover a conclusion could be drawn the level of concentration of SSRIs in the aquatic environment may be of less significance since teleosts have the potential to bioaccumulate SSRIs in tissue over time and in this sense concentrations may reach harmful levels that can cause physiological or behavioural alterations. Continuous studies should refer to chronic tests studies with focus on a field testing environment for understanding of natural conditions and exposure. Furthermore, studies on how ecosystems may be affected should be important to give an overview of the problem with SSRI exposure. As the Baltic Sea is a sensitive environment, studies should preferable be made on species living in this environment.