It is well known that protection of human health and the environment from the risks of hazardous wastes involves evaluation of numerous complex issues. Approximately 4 years ago a few people began to explore the possibility of using expert system techniques to expedite the transfer of professional decision expertise to a wider audience of decision makers. Currently several organizations are developing expert systems to expedite hazardous waste decision making and improve the quality and consistency of resulting decisions. It is anticipated that system development will proliferate during the next few years. Expert systems will change the way in which information is passed between organizations.