Pathogens, particularly Brucella spp., pose a serious threat to human and animal health. In the complex of anti-epidemic and sanitary-hygienic measures aimed at preventing infectious diseases, chemical disinfection plays an important role. This disinfection method is one of the effective, reliable and common ways to combat pathogenic biological agents. An important role is played by modern quaternary ammonium compounds (QAC)-based disinfectants. In relation to chemical disinfectants, the causative agent of brucellosis belongs to the group of low-resistant microorganisms. Solutions of sublimate, creolin, phenol, sulfuric, hydrochloric, nitric and acetic acids, formalin, chloramine, hydrogen peroxide, solutions of disinfectants based on quaternary ammonium compounds (QAC), triamine and polyhexamethylene guanidine (PHMG) have pronounced bactericidal activity against brucellae. However, the instructions for commercial disinfectants note a bactericidal activity against pathogens of particularly dangerous infections (plague, tularemia, cholera and anthrax), but do not indicate antimicrobial properties against Brucella. The purpose of the work was to determine the antimicrobial properties of five commercial disinfectants “Alfadez Forte”, “Aminaz-Plus”, “Veltolen”, “Desarin” and “Laina-med”, used in the disinfection of objects with especially dangerous infections of bacterial etiology. The studies were carried out using the suspension method, according to the manual “Methods of laboratory research and testing of disinfectants to assess their effectiveness and safety.” Three vaccine strains B. melitensis Rev-1, B. abortus 19 BA, B. suis 61 were used as test microbes. As a result of the studies, it was found that commercial disinfectants “Alfadez Forte”, “Aminaz-Plus”, “ Veltolen", "Desarin" and "Lina-med" in the concentrations proposed by the manufacturers in the instructions for use when working with particularly dangerous infections (plague, tularemia, cholera) have bactericidal properties relative to vaccine strains.