Canine mycoplasma Mycoplasma canis is associated with urogenital infections and infertility. The mechanisms of pathogenesis are poorly understood. The main goal of this Master's thesis was to determine adhesion and invasion property of studied Mycoplasma canis strain Larissa on the DH82 canine cell line in vitro. Results showed not only the adhesion abilities of Mycoplasma canis, but also, to a lesser extent, the ability to invade into the DH82 host cell line. In both cases, CFU values reached their peak after 9 hours of the incubation period. Microscopic images revealed, that infection of the DH82 cell line with Mycoplasma canis leads to morphological changes, which were most prominent after 48 hours after infection. The slight drop in viability and increase in number of lysed cells is also present and again, most visible after 48 hours of the incubation period. It looks like that infection of DH82 cells with Mycoplasma canis affects the diameter of the infected cells, which is reduced by about 3 μm. Adhesion onto and invasion into the DH82 cells by Mcoplasma canis in vitro confirms scientific presumption, that adhesion and invasion capabilities in vivo are linked with evasion of the hosts immune response by pathogen, leading to persistent infections, and to mild chronic diseases, which are most common among Mycoplasma canis strains.