As other mountain ranges in Papua New Guinea it is home to many rare species of fauna and flora and is highly biodiverse. The black sicklebill (Epimachus fastuosus) is a threatened species which is known from a few localities in the Bewani and Torricelli mountains. Fiwo, a subspecies of the tenkile (Dendrolagus scottae) tree-kangaroo, is thought to be endemic to the Bewani Mountains. Two frog species described in 2000/2001, Cophixalus bewaniensis and Choerophryne longirostris, are so far only known from the Bewani Mountains.