Found throughout the Southern half of New Guinea, this species is endemic to the island. It was once considered to be a subspecies of the New Guinea crocodile, but is now considered to be a separate species, having split between 3 and 8 million years ago.

It is listed on CITES appendix ii, but is awaiting an assessment of its numbers in the wild. There are thought to be only around 100,000 crocodiles on the island split between the halls and the new guinea crocodile, but its unknown how this number is split between the two species.