Аннотация:Today in the arsenal of specialists there is a wide range of antibacterial drugs, but not all of them meet modern requirements with the position of efficiency, ecological security, addiction of microorganisms and oppression of natural neurohormonal mechanisms of local and shared defenses of the organism. Wide and sometimes unreasonable use of antibiotics in medical and veterinary practice has facilitated development and all-round propagation of antibiotic-resistant and antibiotic-dependent microorganisms. Drug resistance, as a rule, has complex genetic or biochemical basis and in some cases is caused by malfunction of binding and flux of antimicrobial substances in bacterial cells or induction of formation of enzymes, inactivating antibiotic drugs. The research on the use of a new drug Argumistin comprising colloidal silver particles and the substances from the group of quaternary ammonium compound is discussed. Gel-based antiseptic drugs Endometramag-Bio and Khinasept-Gel were used as a comparison. When treating cows with acute endometritis, the drugs were intrauterine-administered up to 4-5 times in a dose of 100 mL. In case of chronic endometritis the drugs were administered in a dose of 70 mL, on alternate days, 3 times. The greatest recovery rate of 78.6% was observed in cows of the trial group with acute endometritis and 87.5% with chronic endometritis. Therefore, Argumistin drug reveals high therapeutic effectiveness as compared with the alternative drugs.