This beautiful frog has an azure-blue hue on the limbs, a sky-blue on its dorsal surface, and a darker blue on its ventral surface. An irregular pattern of dark blue and black spots of various sizes cover this background coloration with the majority of the spotting located on its back as well as head. The pattern of spots is unique to each frog and thus serves as a "fingerprint" to differentiate between individuals. The female is slightly larger and is plumper than the male, with her average body length about 4.5 cm and his only 4 cm.

It is found only in the southernmost part of the South American. It prefers a dark, moist environment, living only near small streams among moss-covered rocks. It typically remains on the ground, but has been found in trees at heights of up to five meters. 

The Blue Poison Dart Frog eats ants, beetles, flies, mites, spiders, termites, maggots, and caterpillars. In captivity, its diet consists primarily of crickets and fruit flies. The toxic compounds (poisons) in their skin come from the ants they eat. In captivity, this species loses its poisonous properties due to the lack of toxic compounds within the food it is fed. Though toxic, they are still preyed upon by snakes and large spiders.