We describe a new species, Telmatobius chusmisensis, from Chusmisa, Iquique Province, northern Chile. The new taxon is diagnosed by characteristics of the adult morphology, osteology, larval external morphology, and chromosomes. The new species is compared with its Chilean congeners and differs from them in presenting all the carpal elements cartilaginous. The tadpole of T. chusmisensis lack intramarginal mental papillae sharing this character with other Chilean species of the genus.