An ancylostomatid Kalicephalus spp. is the common parasitic intestinal nematode of reptiles. West-Asian blunt-nosed viper, a venomous snake found in extensive areas of Iran. Between June - September 2017, two dead viper snakes were referred to the parasitology laboratory and examined for intestinal parasites. Several white elongated roundworms were collected and fixed to identify under light and scanning electron microscopes (SEM) based on morphological and molecular characteristics. For the molecular survey, some parts of identified worms were extracted and the ITS of nuclear ribosomal DNA (rDNA) amplified by PCR reaction. All collected hookworms were taxonomically identified as Kalicephalus viperae viperae and exposited in an individual branch far from of Ancylostomatidae species and close to A. braziliense with 88% discrepancies in the phylogenetic tree. The morphological characteristics and a large part of K. viperea viperea rDNA nucleotide sequence was reported in viper snakes for the first time in the world and Iran.