The authors present the results of a comparative appraisal of a set of species-specific primers in the polymerase chain reaction (PCR) identification of typical and atypical plague pathogen strains. A hundred and seventy-three strains with a species specificity of Y. pestis and 67 heterologous strains were used to appraise the well-known Y. pestis chromosomal DNA-based primers: "3a", "yp2769ms06", "vlml2for/ISrev216", "vlm33/ISfor1754", as well as "JS" specific to Y. pseudotuberculosis". In some plague bacterial strains, the DNA sequences complementary to the primers "3a" and "yp2769ms06" were not found. All conceivable plague pathogen strains were detectable only with the primers "vlml2for/ISrev216" and "vlm33/ISfor1754". The primers "JS" recognized only the strains of pseudotuberculosis causative agent. The DNA of other microorganisms failed to react with none species of primers. For the effective detection and differentiation of typical and atypical Y. pestis strains, the authors propose PCR using a few pairs of primers with the merits of the primers of the group "vlm" and 'JS".