The exact reason why some microorganisms produce surfactants is unclear. However, biosurfactant-producing bacteria are found in higher concentrations in hydrocarbon-contaminated soils. Accordingly, our results also suggest that the capacity to secrete surface-active agents is a common feature among PAH-degrading soil bacteria.Until now, the few researchers who have looked for surfactant production by PAH-degrading bacteria have been unsuccessful. UG2 was reported to display some emulsifying activity when grown on naphthalene, but under our experimental conditions it could not utilize naphthalene or express any naphthalene dioxygenase activity. To our knowledge, this is the first published report of microorganisms producing surface-active compounds while growing on PAHs. Experiments are in progress to characterize the optimal conditions for biosurfactant production on PAHs and to determine the potential role biosurfactants may play in PAH metabolism by the producing organism.