The chemical industry developed over the past century using petroleum as its primary feedstock. A variety of economic, political and social forces are now leading the chemical industry to use or consider renewable plant-based feedstocks in addition to or instead of petroleum. The next century may see a gradual transition away from petroleum as the primary feedstock for chemicals, materials and liquid fuels. If this transition is to occur, and if the chemical industry is to become more sustainable, a considerable amount of research must be done. This paper summarizes the research and development priorities for a more sustainable, or 'green', chemical industry based on renewable plant resources and relies heavily on a recent report of the National Research Council (NRC) of the United States. (C) 2003 Society of Chemical Industry.