Pharmaceuticals are in many cases an indispensable element ofa comfortable and healthy life. Nevertheless, there is also a downsideto the widespread and increasing use of drugs: the occurrenceof their residues in the aquatic environment and in drinking water.Although there is evidence for negative effects of active pharmaceuticalingredients (APIs) in some animal and plant species, it hasnot yet been shown which risks in fact exist for humans and theenvironment. At the same time there is evidence that people willreject drinking water which contains only the smallest traces of APIs,despite claims that such traces are harmless. In this mélange ofhigh uncertainties, subjective risk perception, and the undisputedsocietal benefit of pharmaceuticals, established risk managementprocedures are likely to fail. Addressing this issue, the article willsuggest applying the concept of systemic risk to the case of APIsin drinking water. With this concept as basis a practical approachto risk management will be presented. It draws upon the recentlydeveloped concept of risk governance, as well as the precautionaryprinciple. Finally, concrete measures for risk precaution in thespheres of drug development, handling of drugs, and technicalemissions control in urban water management will be presented