A polyphasic study was undertaken to establish the taxonomic position of a soil isolate that had provisionally been assigned to the genus Rhodococcus. The organism showed a combination of phenotypic properties typical of rhodococci and formed a distinct phyletic line within the Rhodococcus erythropolis 165 rDNA subclade. The organism was readily distinguished from representatives of validly described species classified in this subclade on the basis of DNA-DNA relatedness and phenotypic data. Consequently, it is proposed that the organism be recognized as a novel species of Rhodococcus, Rhodococcus maanshanensis sp. nov. The type strain is strain M712(T) (= AS 4.1720(T) = JCM 11374(T)).