Active microbial degraders of the herbicide prosulfocarb (PSC) were isolated to evaluate their performance in soil with a view to their use for bioremediation. The isolated cultures (a microbial consortium and a Pseudomonas sp. strain) were active when tested in mineral medium with PSC as the only carbon source, but had an adverse effect on the soil indigenous microflora. Biodegradation in the inoculated soils was thus lower than in the uninoculated soil when only the indigenous microflora was present. Further tests showed that the strong affinity of PSC for soil organic matter affected its bioavailability and hence its biodegradation by the inocula. Bioremediation of PSC contaminated soils could thus be undertaken by biostimulation of indigenous microflora.