A novel actinomycete strain, PS7-2T, which produced spore chains borne on the tips of short sporophores, was isolated from soil collected from a temperate peat swamp forest in Phu-Sang National Park, Phayao province, Thailand. The isolate contained glutamic acid, glycine, alanine, 3-hydroxy-diaminopimelic acid and meso-diaminopimelic acid in the cell-wall peptidoglycan. The whole-cell sugars were glucose, mannose, rhamnose and xylose, and the major phospholipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol and phosphatidylethanolamine. The predominant menaquinones were MK-10(H8) and MK-9(H8) and the predominant cellular fatty acids were iso-C15: 0, anteiso-C15: 0 and anteiso-C17: 0. The G+C content of the genomic DNA was 72.3 mol%. On the basis of 16S rRNA gene sequence analysis, strain PS7-2T clustered with members of the genus Asanoa and appeared most closely related to the type strains of Asanoa hainanensis (99.5% sequence similarity), Asanoa iriomotensis (99.0%), Asanoa ishikariensis (98.9%) and Asanoa ferruginea (98.5%). DNA-DNA hybridiza-tions and some physiological and biochemical properties indicated that strain PS7-2T could be readily distinguished from its closest phylogenetic relatives. Based on the phenotypic and genotypic evidence and DNA-DNA relatedness values, strain PS7-2T represents a novel species in the genus Asanoa, for which the name Asanoa siamensis sp. nov. is proposed; the type strain is PS7-2T (5BCC 41921T5NBRC 107932T). © 2013 IUMS.