[3][4] Calling adult males from Santa Teresinha, Bahia had an average snout–vent length of 27.8 and 36.8 mm (1.09 and 1.45 in) in 2008 and 2009, respectively.

The digits are long, laterally expanded, and have developed discs.

[4] Frostius pernambucensis occurs in primary and secondary forests at elevations up to 800 m (2,600 ft) above sea level.

[1] Males call perched in vegetation some 0.2 and 2.5 m (7.9 in and 8 ft 2.4 in) above ground.

[4] The species is threatened by habitat loss caused by agricultural expansion, livestock grazing, clear-cutting, wood plantations and human settlement, and by collection of bromeliads.