The ability of rhamnolipid biosurfactants produced by Pseudomonas aeruginosa UG2 to wash a model hydrocarbon mixture from unsaturated soil columns was studied. Both aliphatic and aromatic hydrocarbons were effectively removed without soil clogging with non-recirculating biosurfactant solutions. Recirculation of wash solutions did not substantially affect washing efficiency. Of the several chemical surfactants tested, only Triton X-100 provided comparable hydrocarbon washing efficiency without soil clogging. The results suggest that UG2 biosurfactants have the potential for remediation of hydrophobic pollutants in unsaturated soil.