Diagnostics of the uterus and fertility control include clinical, bacteriological, cytological and histopathological examinations. Bacteriological studies should be accompanied by cytological and pathological tests, because the presence of inflammatory processes is the most important for diagnosis and prognosis. Although, there is no standard method for the interpretation of cytological examination results for endomentrium, the examination of cytologic swabs from the surface of the uterine mucosal surface is a simple and noninvasive method used as a supplementary examination in mares. In our country this method is recommended in veterinary practice, primarily for the diagnosis of endometritis. Key words: mare, uterus, smear, cytology.