Three species of Steinemema: Steinernema feltiae (Filipjev, 1934), Steinernema kraussei (Steiner, 1923), Steinernema sp. and Heterorhabditis bacteriophora (Poinar, 1976) were recorded from Bulgaria for the first time. Nematodes were isolated from soil samples taken from six natural ecosystems: three near Sofia and three from other parts of the country. Morphometric data are presented for juveniles and males of the studied species.