The taxonomic status of Rhodococcus equi, originally isolated from foal specimens, has been the subject of discussion for a number of years. The chequered history of the taxon has prompted this polyphasic analysis of R. equi strains, close members of the genus Rhodococcus and representatives of other genera classified in the order Corynebacteriales, to establish the taxonomic position of this taxon. Thirty one R. equi strains, including the type strain, were examined for genotypic and numerical taxonomic properties. The resultant data are consistent with their classification in the order Corynebacteriales but the R. equi strains formed a distinct phyletic clade away from representatives of other members of the genus Rhodococcus in the 16S rRNA gene tree. Representatives of this clade shared their highest pairwise 16S rRNA gene sequence similarities with the type strain of Rhodococcus kunmingensis (95.2–98.1 %). However, the R. equi taxon was readily distinguished from R. kunmingensis and from the other members of the order Corynebacteriales using a combination of genotypic, chemotypic and phenotypic properties. On the basis of these data the R. equi strains are considered to represent a new genus. The name proposed for this taxon is Prescottia gen. nov., with Prescottia equi comb. nov. as the type species containing the type strain, C 7T (= ATCC 25729T = ATCC 6939T = CCUG 892T = CIP 54.72T = DSM 20307T = HAMBI 2061T = NBRC 14956T = JCM 1311T = JCM 3209T = LMG 18452T = NBRC 101255T = NCTC 1621T = NRRL B-16538T = VKM Ac-953T).