I describe a new species of hylid frog of the genus Nyctimystes from Fergusson Island off the southeastern peninsula of New Guinea. The new species is distinctive in being of moderate size, lacking a tubercle or lappet on the heel, and in having a vocal sac and slits, palpebral venation of vertically oriented lines with few cross-connections, basal webbing between the fingers, orange-yellow flash markings in the groin and hidden surfaces of the thighs, and a venter heavily flecked with brown. The new species is currently known only from the type locality, but it may range more widely across the D'Entrecasteaux Islands. It is morphologically most similar to N. persimilis from the mountains of the adjacent mainland of New Guinea.