Exposure to airborne polycyclic aromatic hydrocarbons (PAHs) occurring at production of coce and aluminium is one of the major occupational health problems. In workers exposed to airborne PAHs at high concentrations an increased incidence of lung cancer has been found. In the last decade numerous attempts were made to develop methods for the biological monitoring of exposure to this group od compounds. However, some of the methods like determination of thioethers in urine or urinary mutagenicity proved to be influenced to a large extent by cigarette smoking. Determination of 1-hydroxypyrene (1-HP) (pyrene metabolite) in urine seems to be a more promising approach. In a number of investigations relatively good correlation has been found between the concentration of pyrene and PAHs in the air as well as between the level of occupational exposure to pyrene and urinary excretion of 1-HP. The influence of cigarette smoking on the excretion of 1-HP in urine seems to be negligible as compared to the increase in 1-HP excretion in urine resulting from occupational exposure. Further investigations on the kinetics of excretion of 1-HP in urine and the quantitative relationship between the concentration of PAHs in the air and excretion of 1-HP in urine under relatively well controlled conditions are necessary.