The aim of the study was to evaluate biomarkers of exposure to gasoline in petrol station workers by a combined approach of environmental and biological monitoring. The personal exposure to benzene, toluene, ethylbenzene and xylene (BTEX) and the urinary levels of BTEX, methyl tert-butyl ether (U-MTBE), trans,trans-muconic (t,t-MA) and S-phenylmercapturic acids (S-PMA) and cotinine were determined by mass spectrometry coupled chromatographic techniques. U-MTBE levels were strictly influenced by occupational exposure to gasoline, whereas both U-B and S-PMA levels depended from smoking habits and occupational exposure.