We describe a new species of Xenobatrachus from the Bewani and Hunstein Mountains of northwestern Papua New Guinea. It is closely similar to X. mehelyi and X. subcroceus, but it keys out to the X. rostratus species group as defined by Blum and Menzies. It differs from the former species in body size, relative leg length, and advertisement call. It differs from its other 15 congeners in morphological and color pattern attributes and advertisement call, and it represents another frog species apparently endemic to the northern coastal ranges of New Guinea, further supporting identification of this area as a center of regional biotic endemism. This reflects the offshore origin of these ranges in the Solomons Arc system, followed by accretion to the New Guinea mainland during the past ten million years.