Brachycephalus pernix is a small and brightly coloured species of frog in the family Brachycephalidae.

It is endemic to Paraná in southeastern Brazil and only known from a single location at an altitude of 1,135–1,405 m (3,724–4,610 ft) on Serra da Baitaca in Serra da Baitaca State Park.

[2] This diurnal species lives among leaf litter on the floor of Atlantic rainforest.

[3] Its conservation status was last reviewed by the IUCN in 2004 where regarded as data deficient (insufficient information for rating it),[1] but an independent review in 2019 that used IUCN's criteria recommended that B. pernix should be recognised as vulnerable.

[3] The bright pattern is considered aposematic (warning colours) since its skin and organs contain tetrodotoxin and similar toxins.