A high-performance liquid chromatographic method is described for the simultaneous determination of six metabolites of aromatic hydrocarbons: hippuric acid (HA) from toluene; o-, m-, p-methylhippuric acids (o-, m-, p-MHA) from xylene; mandelic acid (MA) and phenylglyoxylic acid (PGA) from styrene and ethylbenzene. Metabolites were first extracted from urine by solid phase extraction with anion exchange resin, then isocratically separated on a C8 column with 3 microns particle size, 10 cm length and 3 mm internal diameter. Mobile phase was prepared diluting 16 mL of tetrahydrofuran, 14 mL of acetronitrile and 5 mL of methanol to 500 mL with phosphoric acid/potassium dihydrogen phosphate buffer 0.01 M (pH 2.7). The internal standard was 3-hydroxybenzoic acid. Chromatographic runs were completed in about 21 min. The accuracy and reproducibility obtained make this method useful for the biological monitoring of occupational exposure to toluene, xylene, styrene and ethylbenzene.