A combined molecular and phenotypic approach was used to determine whether ear mites of the genus Otodectes (Acari: Psoroptidae) belong to a single species. The second internal transcribed spacer (ITS 2) of the rDNA of 16 isolates from 11 cats, two dogs, one arctic fox and two ferrets originating from four different continents was characterized. In addition, mites from dog, cat and arctic fox were investigated morphologically. Sequence comparisons revealed five different, but closely related genotypes which did not segregate according to host species or geographical origin. Morphologically, mites of the three host species did not differ significantly in their body or leg sizes. These investigations support the view that ear mites of the genus Otodectes from different hosts and geographical origins belong to a single species, Otodectes cynotis (Hering).