Eight unidentified Gram-positive, rod-shaped organisms were recovered from the tracheas of apparently healthy black storks (Ciconia nigra) and subjected to a polyphasic taxonomic analysis. Based on cellular morphology and biochemical criteria the isolates were tentatively assigned to the genus Corynebacterium, although three of the organisms did not appear to correspond to any recognized species. Comparative 16S rRNA gene sequencing studies demonstrated that all of the isolates were phylogenetically members of the genus Corynebacterium. Five strains were genotypically identified as representing Corynebacterium falsenii, whereas the remaining three strains represented a hitherto unknown subline, associated with a small subcluster of species that includes Corynebacterium mastitidis and its close relatives. On the basis of phenotypic and phylogenetic evidence, it is proposed that the unknown isolates from black storks represent a novel species within the genus Corynebacterium, for which the Corynebacterium ciconiae sp. nov. is proposed. The type strain is CECT 5779^T (=BS13^T=CCUG 47525^T).