Soil washing is a potentially efficient treatment of various organic and inorganic waste. It separates, segregates, and reduces the volume of solid-phase hazardous materials. Efficiency of this treatment applied for PCBs under laboratory conditions was estimated to be about 60%. Surface contaminants may be removed from soil particles by solubilization in the washing solution and oils and the floated concentrated phase can be then removed and adequately liquidated. Although the washing process has not been realized in a pilot-plant scale, trials simulated in a laboratory confirmed a sufficient efficiency of this method used for the reduction of PCB content in the tested soil.