The 16S rRNA gene sequences of 30 strains representing 23 validated Corynebacterium species and 7 currently non-valid Corynebacterium species were determined. These sequences were aligned with the sequences of other Corynebacterium species and related actinomycete taxa. A comparative sequence analysis revealed that there is considerable phylogenetic depth and internal structure in the genus Corynebacterium. Turicella otitidis and the amycolate species Corynebacterium amycolatum were located at the periphery of the genus Corynebacterium. It was evident that the species of the genus Corynebacterium form a monophyletic association and, together with other chemotype IV and mycolic acid-containing taxa (including the genera Dietzia, Gordona, Mycobacterium, Nocardia, Rhodococcus, and Tsukamurella), form a natural suprageneric group.