Abstract: The present invention is directed to a method for the safe and efficient degradation of Polychlorinated biphenyls (PCBs) in PCB contaminated soil into non-hazardous by products. The method comprises adding a culture containing at least six strains of microorganisms capable of degrading PCBs to PCB contaminated soil, mixing the soil and microorganism culture together and maintaining the culture under stringent conditions which promote the growth of the microorganisms and which stimulate the ability of the microorganisms to degrade the PCBs. The method is cost efficient and well suited for decontaminating soil on a large scale commercial basis.