Two surfactants, Tween 80 and JBR, were investigated for their effect on fluoranthene degradation by a Pseudomonad. Both surfactants enhanced fluoranthene degradation by Pseudomonas alcaligenes PA-10 in shake flask culture. This bacterium was capable of utilising the synthetic surfactant and the biosurfactant as growth substrates and the critical micelle concentration of neither compound inhibited bacterial growth. The biosurfactant JBR significantly increased polycyclic aromatic hydrocarbon (PAH) desorption from soil. Inoculation of fluoranthene-contaminated soil microcosms with P. alcaligenes PA-10 resulted in the removal of significant amounts (45 +/- 5%) of the PAH after 28 days compared to an uninoculated control. Addition of the biosurfactant increased the initial rate of fluoranthene degradation in the inoculated microcosm. The presence of a lower molecular weight PAH, phenanthrene, had a similar effect on the rate of fluoranthene removal.