A Gram-positive-staining, filamentous bacterial strain that developed cylindrical sporangia containing four oval- to rod-shaped spores at the ends of short sporangiophores on branched aerial mycelium was isolated from tropical rainforest soil near a hot spring. The cell-wall peptidoglycan contained meso-diaminopimelic acid, glutamic acid and alanine as cell-wall amino acids; the whole-cell hydrolysate contained rhamnose, madurose, glucose, galactose and 3-O-methylmannose as whole-cell sugars. The predominant menaquinone was MK-9(H(4)). Mycolic acids were not detected. The diagnostic phospholipid was phosphatidylethanolamine. The predominant cellular fatty acids were iso-C(16 : 0) and 10-methylated C(17 : 0). The G+C content of the DNA was 71.1 mol%. The phenotypic and chemotaxonomic analyses showed that the isolate had characteristics typical of members of the genus Planotetraspora. Furthermore, 16S rRNA gene sequence analysis also indicated that this strain belongs to the genus Planotetraspora, but as a putative novel species. Following phenotypic, chemotaxonomic and genotypic studies, the isolate is proposed to be a representative of a novel species, to be named Planotetraspora thailandica sp. nov. The type strain is BCC 21825(T) (=NBRC 104271(T)). An emended description of the genus Planotetraspora is also presented.