Plastic pollution is recognised as a serious worldwide problem in the marine environment, added to which there is mounting evidence for more insidious effects on aquatic ecosystems via freshwater sources and wastewaters. It has been shown that significant quantities of microfibres from washing synthetic fabrics end up in sewage sludge and also escape current water treatment processes. Microparticles can interfere with feeding patterns of aquatic life and expose them to plasticisers and other additives. Plastics can also preferentially sorb persistent, bioaccumulative and toxic pollutants which, if they enter the food chain, pose potential health risks to aquatic and terrestrial higher organisms, including people. This workshop will bring together researchers from marine and freshwater backgrounds to review our current understanding of the risks and knowledge gaps. There will be discussion on how best to address plastic pollution of the aquatic environment and respond to the identified evidence gaps and policy needs.