Sixteen strains isolated from different soils and marine sediments and 'Nocardiopsis trehalosi' VKM Ac-942T were subjected to taxonomic analyses. The morphological and chemotaxonomic characteristics of the strains matched those described for members of the Nocardiopsis. Based on 16S rDNA sequence analysis, DNA-DNA hybridization values and phenotypic characteristics, including the composition of menaquinones and cell wall teichoic acids, two new species are proposed, Nocardiopsis tropica sp. nov. (type strain VKM Ac-1457T) and Nocardiopsis trehalosi sp. nov., nom. rev. (type strain VKM Ac-942T = JCM 3357T = NRRL 12026T). Nocardiopsis dassonvillei VKM Ac-1882T (formerly Nocardiopsis albirubida) differs from other strains of this species by the presence of MK-10 as the major menaquinone, cell wall teichoic acid structure, and numerical analysis based on 115 growth and physiological characteristics. The strain is reclassified as the subspecies Nocardiopsis dassonvillei subsp. albirubida, with VKM Ac-1882T (= DSM 43465T = ATCC 23612T = ISP 5465T) designated the type.