Pareas iwasakii, a rare pareatine snake endemic to Japan, is considered a dietary specialist on land snails. I observed the oviposition and hatchling diet of this species in captivity. One female laid six eggs on 30 September, and one of these eggs hatched on 26 November 2004. The hatchling fed on the soft body of juvenile land snails, leaving empty shells, most likely by extracting the former from the latter using its mandibles as do the adult snakes. This observation suggests that the dietary habits of P. iwasakii do not exhibit ontogenetic changes.