Staphylococci represent one of the main groups of commensal bacteria and opportunistic pathogens of various infections in humans and animals around the world, with the capacity to develop a resistance to different antimicrobial medicines. The resistance to beta-lactam antibiotics is of particular importance. Although the data on the clinical significance and generally on the frequency of colonization in animals, including horses, of methicillin-resistant staphylococci (MRS) are limited, the possibility of spreading between animals and humans has been proven. This, as well as the possibility of horizontal spreading of the gene responsible for the bacteria’s resistance to antibiotics on to other bacteria, makes the methicillin-resistant staphylococci a current public health issue. The aim of this work is to determine, for the first time in Croatia, the incidence of colonization of the nasal cavity with the MRS by examining 101 samples of horse nose swabs. The samples were examined using bacteriological test on selective culture media, and the phenotypic resistance of Staphylococcus bacteria to methicillin was determined by disk diffusion method with oxacillin disk. In a study of 101 sampled horses, 69 (68.13%) isolates of coagulates negative methicillin-resistant staphylococci have been isolated. The results of this study suggest a high incidence of colonization of horse nasal cavity with methicillin-resistant staphylococci.