Morphology of adult parasitic hermaphrodites, free-living males and females, rhabditoid and infective larvae of Rhabdias agkistrodonis Sharpilo, 1976 is described. Adult parasites of the species differ from corresponding stage of other Rhabdias species from snakes in the presence of short cuticular needle on the tip of the tail. Free-living generation stages of R. agkistrodonis have typical rhabditoid morphology. Homogonic infective larvae differ from heterogonic ones in the shape of stoma and oesophagus. Three new hosts: Halys viper (Agkistrodon halys) (Pallas) from Altaiskii Krai (Russia), Okinawa habu (Trimeresurus flavoviridis) (Ilallowell)' and T, elegans (Gray) from Okinawa Island (Japan) are added to the host range of R. agkistrodonis known previously exclusively from short-tailed viper (Agkistrodon blomhoffi) from the Russian Far East.