A rapid, simple, and sensitive method was developed for the determination of three cresol isomers and phenol in urine. The sample was spiked with m-chlorophenol, as internal standard, and hydrolyzed with sulfuric acid at ambient temperature. The hydrolyzed solution was saturated with ammonium sulfate and extracted with ethyl acetate. The extract was injected without derivatization into a gas chromatograph fitted with a flame ionization detector and a glass column packed with 0.1% SP 1000 on Carbopack C. All four analytes, which eluted within 13 minutes, were quantified from standard curves.