A polyphasic taxonomic study was undertaken to establish the status of a novel actinomycete, strain S155(T), isolated from a sand dune soil in Egypt. The organism formed characteristic synnemata-like structures and exhibited chemical and morphological features consistent with its classification in the genus Streptomyces. An almost-complete 16S rRNA gene sequence of the isolate was compared with corresponding sequences of representative streptomycetes. The 16S rRNA gene sequence data supported the assignment of the strain to the genus Streptomyces and showed that it formed a distinct phyletic line; the organism was most similar to the type strains of Streptomyces ruber (97.0 %), Streptomyces rubiginosus (97.0 %), Streptomyces roseiscleroticus (96.9 %) and Streptomyces thermoalcalitolerans (97.1 %). It was readily distinguished from the type strains of these species using a combination of phenotypic properties. On the basis of these results, strain S155(T) (=CGMCC 4.2055(T) =DSM 41902(T)) is proposed as the type strain of the novel species Streptomyces synnematoformans sp. nov.