Cow mastitis is a multifactorial disease caused by the interaction of various factors, including the host, specific pathogens, the environment, the season, and keeping conditions. The purpose of this study is to determine the prevalence of mastitis in farms of the Almaty region (Kazakhstan), identify its pathogens, and study their properties. The authors conducted a study at the Biological Safety Laboratory of the Kazakh National Agrarian Research University using samples from several farms. 430 lactating cows of the Holstein and Alatau breeds were selected, with a total of 468 samples over two years. The ability to form biofilm in the isolated strains, as well as antibio tic sensitivity, was studied. Most of the isolated strains were Staphylococcus aureus, Staphylococcus epidermidis and Staphylococcus haemolyticus. The cultures were isolated using microbiological methods, and DNA was analyzed using the CAMOMILE-NKMag-PCR kit. The results showed that the prevalence of mastitis in the Almaty region was 27.2%, mainly in the form of a subclinical manifestation. The authors also found a link between the degree of morbidity and the age of cows, as well as the number of calvings. Among the investigated strains, only 4.3% did not form biofilm. A high prevalence of antibiotic resistance was identified, and methicillin-resistant strains were isolated among S. aureus and S. epidermidis.