A comparative study of acute toxicity of nifuroxazide preparations in form of suspension has been carried out. Mature individuals of white mice (weighing 18-20 g at the age of 8-9 weeks) and rats (weighing 160-180 g at the age of 13-14 weeks) of both sexes were under observation. The administration of the suspensions was performed in increasing doses by Litchfield-Wilcoxon, dosing was carried out by volume on the total mass of the suspension. The recorded indicators were mortality, time of death of animals, symptoms of poisoning, autopsy, description of animals at the end of the study, determination of mass coefficients of internal organs.The compared drugs («Nifuroxazide», suspension for oral administration 200 mg/5 ml, LP 004858 dated 23.05.2018 and «Enterofuril», suspension for oral administration 200 mg/5 ml N014624/02 dated 06.11.2008) are equivalent in terms of acute toxicity, belonging to class VI of relatively harmless drugs, have similarities in the parameters of acute toxicity, the picture of intoxication is the same, and there are not detected signs of damage of internal organs.