The spectrophotometric determination of protein-bound fucose is badly compromised by spurious chromagens developed from protein degradation products. To minimize the contribution of these spurious products to the color yield of fucose, the glycoprotein was partially hydrolyzed in dilute acid, thus releasing the terminal carbohydrate from the protein moieties, and the residual protein was removed with trichloroacetic acid. That the fucose content of this supernatant was real was confirmed by paper chromatography and spectral studies.The spurious chromagens were shown to result from the interaction of protein degradation products and galactose.