The metabolism of furfural was investigated in Sprague‐Dawley (SD) rats. Analytical methodology was developed to identify urinary metabolites by gas chromatography‐mass spectrometry (GC‐MS). Ten adult male SD rats (average weight: 490±20 g) were administered a single oral dose of furfural (50 mg/ kg/rat) and urines were collected for 3 consecutive days. Freshly voided urine was obtained from the rats and analyzed for the presence of metabolites. A 2mL urine sample was adjusted to pH 1.4 using6NH2SO4, followed by ethyl acetate extraction (2x4mL). The extract was evaporated and dissolved in a mixture of ethyl ether/methanol (9/1) for methylation with diazomethane. The mixture was evaporated to near dryness and dissolved in 2mL methanol. Identification of the metabolites as methyl esters by comparison with synthetic samples was conducted by gas chromatography on a DB‐5 capillary column. Further identification of the metabolites was conducted by mass spectrometry which revealed peaks characteristic of 2‐furoic acid, 2‐furoylglycine, the trans isomer of 2‐furanacrylic acid and the trans isomer of 2‐furanacryloylgIycine. The results of these metabolism studies indicate that 2‐furoylglycine in the major urinary metabolite of furfural, followed by unconjugated 2‐furoic acid, 2‐furanacryloylglycine and 2‐furanacrylic acid.