Re-evaluation of the taxonomic position of strain K-252T, which produces the compound K-252a, showed that the strain does not belong to the genus Nocardiopsis suggested previously. Strain K-252T formed aerial mycelia with long spore chains, and hyphal fragmentation was not observed. The cell wall chemotype of the strain was III/B, the major menaquinone was MK-9 (III, VIII-H4), the phospholipid pattern was PIV and the major cellular fatty acids were 10Me-C17:0, iso-C16:0 and C16:0. Phylogenetic analysis of the 16S rRNA sequence showed that strain K-252T was clustered in the Nonomuraea group. Furthermore, on the basis of DNA-DNA reassociation and phenotypic data, strain K-252T (= NRRL 15532T) was classified as a new species of the genus Nonomuraea. This strain is proposed as Nonomuraea longicatena sp. nov.