The taxonomic position of actinomycete strain NN276(T), isolated from cave soil, was studied using the polyphasic taxonomic approach. A phylogenetic tree based on 16S ribosomal RNA (rRNA) gene sequences showed that the isolate formed a distinct evolutionary linage with the genus Microbispora, with M. mesophila JCM 3151(T) as its closest phylogenetic neighbor (97.9% similarity). The organism contained meso-diaminopimelic acid and the N-acetyl type of peptidoglycan. Madurose was detected in the whole-cell hydrolasate. The predominant menaquinones were MK-9(H(4)), MK-9(H(2)) and MK-9. Mycolic acids were not detected. Major phospholipids were diphosphatidylglycerol, hydroxy-phosphatidylethanolamine, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositol mannoside. The major cellular fatty acid was iso-C(16: 0) and G+C content 70 mol%. DNA-DNA hybridization demonstrated that the isolate was distinct from M. mesophila JCM 3151(T). On the basis of phenotypic and genotypic data, it is proposed that strain NN276(T) represents a novel species of the genus Microbispora, hence the name Microbispora thailandensis sp. nov. The type strain is strain NN276(T) (=BCC 41490(T)=NRRL B-24806(T)=NBRC 107569(T)).