A variety of chemicals and drugs are used in aquaculture for purposes such as sediment and water management, enhancement of natural aquatic productivity, transport of live organisms, feed formulation, manipulation and enhancement of reproduction, growth promotion, health management, processing and adding value to the final product. The reliance on these chemicals and drugs has become greater with the intensification of production, and their environmental toxicity has to be questioned. In this document, we give an overview of environmental aspects concerning drug and chemical use in aquaculture.