The aim of this study was to assess the seroprevalence of antibodies against Yersinia in the rural and urban population and to determine the frequency of particular serotypes of Yersinia enterocolitica and Yersinia pseudotuberculosis. 472 sera were examined, 257 of rural inhabitants and 215 of urban inhabitants. The survey was carried out by passive hemagglutination test with the antigens of Yersinia serotypes considered pathogenic for humans: Y. enterocolitica 03, 05, 06, 08, 09 and Y. pseudotuberculosis I and III. In the examined rural population positive reactions to Yersinia antigens were significantly more frequent than in the examined urban population (42% versus 20%, p<0.0001). The most frequent reactions were against Y. enterocolitica serotypes 05 and 08.