Intoxications by S. aureus enterotoxins are predominant in our country, together with enteric infections by Salmonella spp. For lack of a specific therapy the possibility was examined to neutralize orally provided toxin in vivo. For this purpose before and after the intoxication, respectively, antitoxin and normal rabbit serum as a control were also applied per os. In extensive trials SPF-mice were used as a model in spite of their insensitivity to staphylococcal toxins even with 10000 times the emetic dose for monkeys. By serological means, the rate of free toxin in stomach, intestinal contents and fecal matter after and before application of antiserum was identified as an indicator for the neutralization of the toxin in vivo. As toxin, S. aureus enterotoxin B (SEB) was used which could be identified in the samples up to three hours after oral feeding. Antiserum was obtained by immunization of rabbits with toxoid. The application of antiserum one hour after intoxication resulted in an average reduction of free toxin in the intestine of 87,5 and 86,5%, (10 independent trials) one and two hours, respectively after serum administration. In contrast, administration of antiserum one hour before experimental intoxication did not produce statistically confirmed differences between the experimental and the control animals.