[3] The specific name pefauri honours Jaime Eduardo Péfaur Vega, a Chilean ecologist and herpetologist[5] and colleague of the authors who described the species.

Darker mottling is often present, as are small cream or light grey spots.

[4] The type locality is a small high-altitude (3,200 m (10,500 ft) above sea level) stream without vegetation.

The species is fully aquatic;[1][2] the holotype was found at night underwater in a half-meter deep stream pool.

[6] Telmatobius pefauri is threatened by habitat loss extraction of water from streams for cattle ranching and human use.