A novel enzyme-based colorimetric method for hista-mine determination in fish meal was developed. It is based upon hista-mine oxidation by diamine oxidase and detection of the hydrogen peroxide generated using a peroxidase catalyzed reaction coupled with phenol-aminoantipyrine. At optimum assay conditions (temperature: 50°C, pH: 9.0), this technique allowed the accurate quantification of histamine + putrescine + cadaverine levels (amine index) between 200 to 2000 ppm. The method represents a good alternative for the rapid detection of potentially toxic fish meal. © 1999 Taylor and Francis Group, LLC.