Biosurfactants are surfactants that are produced extracellularly or as part of the cell membrane by bacteria, yeasts and fungi. Examples include Pseudomonas aeruginosa which produces rhamnolipids, Candida (formerly Torulopsis) bombicola, one of the few yeasts to produce biosurfactants, which produces high yields of sophorolipids from vegetable oils and sugars and Bacillus subtilis which produces a lipopeptide called surfactin. This review includes environmental applications of these biosurfactants for soil and water treatment. Biosurfactant applications in the environmental industries are promising due to their biodegradability, low toxicity and effectiveness in enhancing biodegradation and solubilization of low solubility compounds. However, more information is needed to be able to predict and model their behaviour. Full scale tests will be required. The role of biosurfactants in natural attenuation processes has not been determined. Very little information is available concerning the influence of soil components on the remediation process with biosurfactants. As most of the research until now has been performed with rhamnolipids, other biosurfactants need to be investigated as they may have more promising properties.