The poorly known Telmatobius montanus was rediscovered in the high Andean mountains between Mendoza and Talca on the Argentinian- Chilean frontier. Morphological characters of the adults and tadpoles are described. There is convergence in male secondary sex characters toward the leptodactylid frogs of the genus Eupsophus (nodosus group).Material digitalizado en SEDICI gracias a la colaboración del Dr. Jorge Williams (FCNM-UNLP).Facultad de Ciencias Naturales y Muse