The transfer of organic pollutants was studied through soil columns using 13[C]-labelled pentachlorophenol (PCP) as a model compound. The organic carbon content and the 13[C]/12[C] ratio were measured in two soil sections, 0-3 cm and 3-6 cm, and in percolated water using an Elemental Analyser coupled with a Magnetic Mass Sector. The mass balance of carbon was evaluated and the amount of PCP was calculated in each compartment of the soil-water systems. The results show that more than 80% of the PCP-derived 13[C] remained in the upper layer of the soil column. Approximately 20% was transferred to the lower soil layer, and less than 1% was found in the water leachates. The 13[C]-labelled tracers may thus be used as an alternative to radioactive compounds to follow the fate of organic pollutants in soil and water under field conditions.