DNA-DNA hybridization experiments and comparative 165 rDNA sequence analysis revealed that six isolates from purulent joint and lung infections in calves, from a lung lesion in a sheep, and from a joint infection of a pig represented a novel species belonging to the genus Globicatella. Whole-cell protein electrophoresis and biochemical activity testing revealed that the isolates formed a homogeneous group differing from Globicatella sanguinis, the only species of this genus described to date. These animal isolates were classified as Globicatella sulfidifaciens sp. nov. with LMG 188441 (= CCUG 44365T), isolated from the lung of a calf, as the type strain. A detailed description of its phenotypic characteristics is presented. Hydrogen sulphide production was found to be a very useful diagnostic feature.