A description is given of Steinernema anatoliense n. sp. ( Rhabditida: Steinernematidae), an entomopathogenic nematode isolated from soil samples collected in the locality of Kars, East Anatolia, Turkey. Cross-hybridisation, morphological and molecular studies ( RFLP analysis) indicated the distinctness of S. anatoliense n. sp. from other Steinernema species. Diagnostic characters include: body length of third-stage infective juvenile (507 - 580 mum); lateral field pattern with 6-8 longitudinal ridges; tail shape of the first generation male with a cuticular mucro; shape of the spicules and gubernaculum; and arrangement of the genital papillae. In addition, RFLP analysis of the ITS region of rDNA shows S. anatoliense n. sp. to be distinct from 50 other Steinernema species and isolates.