In hazardous waste management, solidification/stabilization (S/S) is a term normally used to designate a technology employing additives to alter hazardous waste to make it non-hazardous or acceptable for current land disposal requirements. The use of this technology to treat hazardous waste may become more important as regulations restrict the use of land for disposing of hazardous waste. The paper reviews the technology and provides information to help assess its potential role in managing hazardous waste. Information is provided to assist the proper selection, use, and evaluation of S/S technologies. Regulatory factors affecting its use are also discussed.