During the last 10 years, characterizing the ecotoxicity of hospital wastewater (HWW) has focused on different aspects. Initially, it mainly consisted in collecting information on ecotoxic substances used in hospitals (disinfectants, detergents, pharmaceuticals, etc.). Thereafter, experimental measurements of ecotoxicity on whole effluent were carried out in different hospitals. These data have shown the generally high ecotoxicity of this effluent, and its considerable evolution during a single day and a full year of activity. In addition, the bioaccumulation of certain pharmaceuticals in organisms and trophic chains has been demonstrated, which contributes to increasing the risk of these molecules. The interactions between the molecules present in HWW have also been the subject of studies. The collection of all these data have enabled researchers and managers to carry out the first ecotoxicological risk assessment studies in different hospitals around the world. It is now necessary to complete these works, in order to refine the characterization of HWW ecotoxicity and consolidate the methodologies of ecotoxicological risk assessment formulated.