The taxonomy of the poorly known South American goblin spider genus Birabenella Grismado (Araneae: Oonopidae) is updated in light of recently collected material. Three new species are described: B. kamanchaca, from northern Chile, B. portai, from northwestern Argentina, and B. chincha, from southern Peru, where the genus is reported for the first time. The diagnosis of the genus is updated; the presence of the ventral digitiform projection on the male copulatory bulb in the three newly described species supports this character as a putative synapomorphy for the genus. Additionally, all species in this genus possess unipectinate tarsal claws. Preliminary observations indicate that there is some degree of variability in tarsal organ morphology.