The aim of this study was to compare the activity of hydrolytic enzymes in yeast-like fungi isolated from cows with clinical and subclinical forms of mastitis. The study included 91 strains of fungi of the genera Candida, Trichosporon and Geotrichum isolated from cows with fungal inflammations of the udder. Fungal colonies were identified by the API 20 C AUX test (bioMerieux) and the APIWEB computer program (bioMerieux). The yeast enzyme profile was determined by the API ZYM test (bioMerieux, Poland). API ZYM is a semiquantitative micromethod capable of quickly identifying 19 enzymatic reactions. Leucine arylamidase showed the highest enzyme activity. High enzymatic activity was also shown by acid phosphatase XI, and the average activity was shown by esterase, esterase lipase, and α-glucosidase. Minimal activity (or none) was shown by α-fukosidase, α-mannosidase, β-glucuronidase, both galactosidases (α and β), α-chymotrypsin and trypsin. Our study demonstrated statistically significant differences in esterase activity between the Candida and the Trichosporon and between the Candida and the Geotrichum genera, in lipase esterase activity between the Trichosporon and fungi of the Candida and the Geotrichum genera, in â-galactosidase activity between the Candida and fungi of the Trichosporon and the Geotrichum genera, and in valine arylamidase activity between the Geotrichum and the Candida types. Yeast-like fungi produce a large number of enzymes that affect the course of a fungal infection. Enzyme activity can therefore disrupt the fungus-udder balance in favor of the fungus.