The application of fire retardants for forest fire prevention purposes can result in chemicals leaching from soil to the drainage water during the annual rainfall period. In addition, wildland fires can have an impact on the leaching of various chemicals from treated forest soils. In leachates, large concentrations of phosphorus (P) – one of the major components of long-term retardants – could affect the groundwater quality. In this present study, the leaching of phosphorus (contained in FIRE-TROL 931 – a long-term fire retardant based on polyphosphates) from a typical Mediterranean forest soil, was studied at the laboratory scale. The concentrations of P from the application of retardant in the resulting leachates from pots, containing forest soil and pine trees (Pinus halepensis), alone and in combination with fire, were determined by an inductively coupled plasma analytical method. The leaching of P, under the conditions used, was found to be a small percentage of the initially applied P quantities. However, it was different among the treated samples affected by both plant and fire conditions.