ABSTRACT This study was aimed to evaluate urinary benzene, toluene, ethylbenzene, m + p-xylene, o-xylene (BTEX), as biomarkers of exposure to BTEX. Total of 76 first-morning void urine samples were collected from Tehran general population. Urinary BTEX content were analysed by headspace gas chromatography–mass spectrometry. Median urinary levels of these chemicals were 87.5, 60.5, 98, 65.6, 47 and 49 ng/L, respectively. Investigating the status of smoking habit and biomarkers shows that there is a significant difference between tobacco use and no tobacco use, so that urinary BTEX concentrations were higher in smokers than in non-smokers. The correlation analysis between independent variables and pollutants showed that the employment status and tobacco use habits for benzene, the tobacco use habits and employment habits for ethylbenzene, tobacco use habits for toluene, employment status and tobacco use habits for m.p.xylene, employment status and tobacco use habits for o.xylene, had the highest level of significance, and age, sex, and traffic status of place of residence had the least significance level for all pollutants. The biological monitoring is beneficial using urinary samples to evaluate the exposure with BTEX. Given the ease of rapidly obtaining urine samples, they represent a non-invasive alternative to blood chemical analysis.