A new scansorial species of Cophixalus is described from lower montane mossy rain forest in the Moro and Moran areas of Southern Highlands Province in Papua New Guinea. It can be distinguished from all other Cophixalus species in New Guinea by the combination of relatively small size (15.2–19.2 mm snout–vent [SVL]; N  =  10), possession of a single distinct spiniform tubercle on the upper eyelid and a series of spiniform tubercles on the hind limb, tuberculate skin, well developed discs on all digits except the first finger, absence of distinct brown or back lateral markings on the head, and a call consisting of 26–33 musical peeping notes.