The purpose of the research is conducting pharmaco-toxicological assessment of Gelmintal Mini Syrup based on a combination of moxidectin and toltrazuril. Materials and methods. The study was carried out on 64 white male rats and 40 white mice. Each animal species was divided into 4 equivalent groups of 6–10 animals each. When studying acute toxicity, the drug was administered in the form of a syrup (without dilution) to animals once at doses of 11 400, 22 800 and 28 500 mg/kg; when studying subchronic toxicity, the drug was administered daily for 14 days at doses of 570, 1425 and 2850 mg/kg (1/10 and 1/20 and 1/50 of the maximum possible dose administered into the stomach according to the vivisection results). When studying acute toxicity, the animals were followed up for 14 days; we recorded the general condition and behavior of the animals, changes in their body weight, the manifestation of toxic symptoms or possible death. When studying subchronic toxicity, the animals were followed up during the entire period of the drug use (14 days); on the 15th and 24th days of the experiment, we performed euthanasia, collected the blood to determine hematological and biochemical values, and carried out macroscopic examination of the organs. Results and discussion. We did not record the animals’ death at doses of 11 400, 22 800 and 28 500 mg/kg; and no signs of intoxication were noted for the entire follow-up period. LD50 of Gelmintal Mini Syrup exceeds the dose of 28500 mg/kg, i.e. the drug is classified as the 4th hazard class. The results of the studied subchronic toxicity showed that the drug was inactive at doses of 570 mg/kg, 1425 and 2850 mg/kg when administered orally for 14 days.