The aim of this work was to establish a level of polycyclic aromatic hydrocarbons (PAHs, recognised by the World Health Organisation as mutagenic and carcinogenic compounds) in samples of soil collected along the ring road in city Siedlce, which is an element of the main route Berlin-Moscow. Our investigation was carried out in selected points of collecting the samples since April to October 2000, i.e. in a period of growth and final vegetation of plants. Analysis was carried out using Solid Phase Extraction (SPE) and re-verse phase High Performance Liquid Chromatography (HPLC). Concentrations of individual compounds were between 10-7 and 10-9mg kg-1.