The study was conducted to determine yeasts present in the gastrointestinal tract (GIT) of piglets kept under experimental farm (EF) and commercial farm (CF) conditions. Ninety five German Landrace full- and half-sibling piglets were sacrificed at 39 days of age. Sixty eight piglets were weaned at 28th day of life, when they were offered one diet ad libitum. Twenty seven piglets remained unweaned by their dams. None of the piglets received any creep feed before weaning. Digesta samples were collected from 1/3 distal small intestine (SI), caecum and proximal colon. One hundred seventy three colonies of isolated yeasts were characterized by sequence analysis of the PCR-amplified D1/D2 domain of the 26S rRNA gene with following alignment of the recovered sequences to GenBank entries. From the 17 phylotypes found, isolates most closely related to Galactomyces geotrichum, Kazachstania slooffiae and Candida catenulata dominated in the GIT of CF piglets. Kazachstania slooffiae and Candida glabrata dominated in GIT of EF piglets. Sørenson and Morisita-Horn similarity indices between farms were low (0.44 and 0.54 respectively) and the Simpson diversity index was higher for EF (7.58) than for CF (4.34). The study brings new data on yeasts composition in the pig GIT and shows differences in yeasts biodiversity between farms operated at different hygiene conditions.