Four Gram-positive, rod- or coccus-shaped bacterial strains, KSL-1(T), KSL-9, KSL-10 and KSL-12, were isolated from an alkaline serpentinite soil in Korea, and their taxonomic positions were investigated in a polyphasic study. The four strains exhibited no difference in their 16S rRNA gene sequences. Phylogenetic analyses based on 16S rRNA gene sequences showed that the four strains were phylogenetically affiliated to the genus Nocardioides. The four strains had cell-wall peptidoglycan based on ll-diaminopimelic acid as the diamino acid, indicating wall chemotype I. The predominant menaquinone detected in the four strains was MK-8(H(4)). The major fatty acid components were iso-C(16 : 0), 10-methyl-C(18 : 0), C(18 : 1)omega9c and C(17 : 1)omega6c. The DNA G+C contents were 72.4-73.6 mol%. The four strains exhibited 16S rRNA gene sequence similarity levels of 94.0-96.3 % to the type strains of Nocardioides species with validly published names. DNA-DNA relatedness levels between the four strains were 85-91 %. On the basis of phenotypic properties, phylogenetic distinctiveness and genotypic relatedness, strains KSL-1(T), KSL-9, KSL-10 and KSL-12 were classified in the genus Nocardioides as members of a novel species, Nocardioides alkalitolerans sp. nov. The type strain is strain KSL-1(T) (=KCTC 19037(T)=DSM 16699(T)).