Ilam Province in southwest Iran possesses varied climatic and geographical conditions leading to rich biodiversity. An investigating of the status of snakes in the province was carried out from June 2005 to March 2010. A total of 103 specimens were collected and identified. Six families, 20 genera, and 26 species are represented, including Boidae: Eryx (Eryx) jaculus turcicus, Colubridae: Coluber andreanus, Dolichophis jugularis, Eirenis collaris, Eirenis punctatolineatus, Hemorrhois nummifer, Hemorrhois ravergieri, Malpolon insignitus, Malpolon moilensis, Natrix tessellata, Platyceps najadum, Platyceps rhodorachis, Psammophis schokari, Pseudocyclophis Persicus, Spalerosophis diadema, Spalerosophis microlepis, Telescopus tessellatus, Elapidae: Walterinnesia morgani, Leptotyphlopidae: Myriopholis macrorhyncha, Viperidae: Cerastes gasperettii, MacroVIPERA LEBETINA, Pseudocerastes persicus, Pseudocerastes urarachnoides, and Typhlopidae: Typhlops vermicularis. With respect to the data which provided by Latifi (2000), more than 77% of the snakes are reported for the first time in this region. The Colubridae showed the highest species diversity among the families represented, with 16 species.