A sensitive and reliable procedure is described for the determination of ten most important phenolic metabolites of benzene, toluene, xylenes and ethylbenzene. The urine is acidified with sulphuric acid and simultaneously steam-distilled. The distillate is extracted with dichloromethane. The organic phase is reduced in volume for tenfold enrichment. The gas-chromatographic determination is performed on a fused silica capillary (SE 54; 30 m) by FID. For calibration, aqueous standards are subjected to the same treatment as the urinary samples. 3-Ethylphenol is used for internal standardization. For ten alkylphenols (phenol; o- and p-cresol;dl-1- and 2-phenylethanol; 3-methylbenzyl alcohol; 2-ethylphenol; 2,4-, 2,3- and 3,4-dimethylphenol) within-series imprecision has been evaluated for two concentrations (n=10, ¯x=0.9–41.7 mg/l,s=2.3–16.8%). The recovery rates range between 89 and 109%. The detection limit is 0.3 mg/l. Linearity has been tested up to 50