This study assessed the exposure of coke-oven workers to polycyclic aromatic hydrocarbons (PAH) based on two methods of biological monitoring (urinary mutagenicity by Ames test and urinary 1-hydroxypyrene) and concentrations of benzo(a)pyrene in the air collected by personal sampling. The coke-oven workers were classified into four job categories. There was no significant correlation among three methods applied. According to all methods, the workers most exposed to PAH were those working at the topside area of the coke plant, Coke-oven workers excreted significantly more mutagenic substances and 1-hydroxypyrene (HpU) in urine than the controls. Mutagenic substances in urine of coke-oven workers and the control group were detected only with TA98 after metabolic activation. Median HpU levels of coke-oven workers classified into three job categories (A, B, C) exceeded the biological exposure limit. The effect of smoking on urinary mutagenicity and urinary 1-hydroxypyrene was statistically significant.