The enzyme-linked immunospecific assay (ELISA) is equally as sensitive as the radioimmunoassay (RIA) for detecting staphylococcal enterotoxins (SE). The substitution of an enzyme in ELISA for I-125 in RIA results in a more stable reagent and enables quantitation spectrophotometrically or, with appropriate enzymes, semi-quantitation by visual estimation. Assay procedures identical in principle to RIA are employed with, of course, the necessity to avoid the presence of enzyme inhibitors. To date, nanogram quantities of SEA, SEB and SEC have been successfully measured in food extracts. In common with RIA, sensitivity is decreased by the presence of food materials.