The genera Campylobacter, Arcobacter, Helicobacter, Wolinella, and “Flexispira” constitute, within the class Proteobacteria, a separate eubacterial lineage identified as rRNA superfamily VI. A considerable number of common genotypic and phenotypic features differentiate the genera Campylobacter and Arcobacter from the other members of this group. Therefore, we propose that the genera Campylobacter and Arcobacter should be included in a separate family, for which the name Campylobacteraceae is proposed.