The constant release of pharmaceuticals into the environment can lead to pollution of water and soils which might constitute a risk to human and other living organisms. Residues of common pharmaceuticals such as painkillers, antimicrobials, antidepressants, contraceptives or antiparasitics may enter the environment during manufacturing and disposal processes. The main sources of releases, however, are human consumption and veterinary use. Due to the metabolic stability of some pharmaceuticals up to 90% of the active ingredients are excreted and end up in the wastewater system and finally in the environment – e.g. accumulated in the Baltic Sea and its living organisms.The EU and its Member States have in the past few years increasingly recognised the challenge of pharmaceuticals in the environment (PIE). This is exemplified first and foremost by the European Commission’s Strategic Approach to Pharmaceuticals in the Environment, but also initiatives at the national level aiming at closing main knowledge gaps in the field, comprehensive monitoring systems and more surveys to detect the occurrence of pharmaceuticals in surface and ground water. Moreover, the OECD has recently published a report on pharmaceutical residues in freshwater that calls for a better understanding of the effects of pharmaceuticals in the environment and policy actions.However, this has not yet led to the development of indicators and threshold values at the EU level that aid Member States in implementing systematic monitoring schemes for PIE. As long as this situation persists and as long as we still do not sufficiently understand the effects of pharmaceutical residues on the ecosystem and on human health, the question arises: What can be done about PIE at the regional level? The answer to this lies in the precautionary principle – i.e. taking action to prevent harm to the environment even without having exact knowledge of all facets of the problem.