Two actinomycete strains, TT2-10(T) and TT2-3, which produced long spore chains (more than 10 spores per chain), were isolated from peat swamp forest soil in Pattaloong Province, Thailand. Their taxonomic positions were determined using a polyphasic approach. The chemotaxonomic characteristics of these strains coincided with those of the family Micromonosporaceae, i.e. cell-wall chemotype II, muramic acid of the N-glycolyl type, whole-cell sugar pattern D and type II phospholipids. Analysis of the 16S rRNA gene sequences also indicated that these strains constitute a distinct lineage within the family Micromonosporaceae, sharing 91.3-93.8 % sequence similarity with members of this family. On the basis of their phenotypic and genotypic characteristics and their phylogenetic position, these strains represent a novel genus and species, for which the name Actinocatenispora thailandica gen. nov., sp. nov. is proposed. The type strain of Actinocatenispora thailandica is strain TT2-10(T) (=JCM 12343(T)=PCU 235(T)=DSM 44816(T)).