Solvent extraction of contaminated soils, sludges, and sediments has been successfully completed at a number of Superfund sites. Each commercialized process uses a unique operating system to extract organic contaminants from solids. These operating systems may be classified by the properties of the solvents each utilizes: (1) standard solvents, (2) near-critical fluids/liquified gases, and (3) critical solution temperature solvents. The paper discusses pretreatment and posttreatment requirements, and discusses the operating systems of the solvent extraction system currently in the Superfund Innovative Technology Evaluation (SITE) Program. Future demonstrations of these technologies by the U.S. EPA's Superfund Innovative Technology Evaluation Program will provide additional information regarding the efficacy of these processes. Copyright (c) 1992 Air and Waste Management Association).