Pharmaceuticals in the aquatic environment are trace contaminants of growing importance in environmental health due to their physiologically active nature. Pharmaceuticals could affect non-target species and might eventually damage sustainability of susceptible populations in the ecosystem. Potentials for health consequences among susceptible human population cannot be ruled out since long-term exposure to cocktails of pharmaceuticals, which might be present in drinking water, is possible. Selection of antibiotic resistant microorganisms is of another concern. In order to understand, and if needed, to properly address the environmental health issues of pharmaceutical residues, knowledge gaps need to be filled. Knowledge gaps exist in many important areas such as prioritization of target pharmaceuticals for further risk studies, occurrence patterns in different environments, chronic toxicities, and toxicities of pharmaceutical mixtures. Appropriate treatment technologies for drinking water and wastewater could be developed when they are deemed necessary. One of the simplest, yet most efficient measures that could be undertaken is to implement a return program for unused or expired drugs. In addition, implementation of environmental risk assessment frameworks for pharmaceuticals would make it possible to efficiently manage potential environmental health problems associated with pharmaceutical residues in the environment.