The purpose of this study was to determine the contamination of the skin of the palms of workers employed on a dairy cattle farm and to evaluate the disinfectant efficacy of selected preparations against isolated microorganisms. Samples were collected by direct swabbing method from employees while performing their duties on the cattle farm. Subsequently, identification to the species level of the obtained isolates was carried out using culture and biochemical methods. For the labeled bacteria, MIC (minimal inhibitory concertation) and MBC (minimal bactericidal concentrations) determinations were performed against four selected disinfectants using the broth microdilution method. The presence of opportunistic microorganisms belonging to both Gram-negative and Gram-positive bacteria, including spore-forming flora, was determined in the biological material. Bactericidal activity (MBC/MIC ≤ 4) was demonstrated for all disinfectants against bacteria used in the study, except for P2 disinfectant against Serratia rubidae. Gram-negative bacteria were less sensitive to the tested preparations compared to Gram-positive bacteria, with MIC values ranging from 1 to 4 mg/mL and 0.25 to 4 mg/mL, respectively. The P2 disinfectant showed the best antimicrobial properties against both Gram-positive and Gram-negative bacteria. In view of the increasing resistance of microorganisms to biocides, it is necessary to monitor the resistance of pathogens and environmental microorganisms to the cleaning and disinfecting preparations used, as a prevention of the transmission of pathogenic microorganisms to the environment and occupational diseases among farmers.