We describe an assay for acrolein in urine, employing derivatization with m-aminophenol in the presence of ferrous sulfate solution in sulfuric acid. The derivative (7-OH quinoline; DER) and the internal standard (quinine-bisulfate; IS) were separated on a l0-µm particle, 8 mm × 10-cm C18 cartridge in conjunction with a radial compression system using a mixture of 0.05 M dibasic ammonium phosphate solution (pH 2.5):acetonitrile:methanol (92:6:2) at a flow rate of 3 mL/min as a mobile phase. The effluent was monitored fluorometrically at excitation and emission wavelengths of 360 and 495 nm, respectively. The retention times of DER and IS under these conditions were 4.3 and 26 min, respectively, and no interference in the assay from any endogenous substance or other concomitantly used drug was observed. The assay was highly linear (r> 0.994) in the range 1–20 µg/mL of acrolein in urine (CV at different concentrations, ≤7.9%). This method can serve to monitor acrolein pharmacokinetics in patients.