This report was developed as part of the SEA circular project – Reducing marine litter by addressing the management of the plastic value chain in South-East Asia – implemented by the United Nations Environment Programme (UNEP) and the Coordinating Body on the Seas of East Asia (COBSEA), with funding support from the Government of Sweden. This study on plastic material flow and value chain analysis (Thailand) provides the most recent primary and secondary data available on plastic waste management in the country, focusing on types of plastic packaging and products being produced and recycled, waste forms and the ways in which waste is being managed and mismanaged, and estimates of plastic waste leakage.