Negotiations have started for an international treaty to solve the global problem of plastic pollution. This agreement and other actions need reliable measurements. It was the objective of this project to analyze and recommend indicators for plastic pollution, which are relevant, easy to measure and comprehensive. Most losses to the environment are larger plastic items, which eventually break down to microplastics. Mismanaged waste is an important source of plastic pollution, but difficult to measure. A set of complementary indicators could include plastic production/use, recycling rates, plastics in wastewater and rivers, beach litter, floating microplastics and plastic particles that are taken up by animals, e.g. seabirds. A holistic approach to plastic losses along the value chain and plastic accumulation in the environment would improve our understanding and related actions.