The New Guinea Quoll is widespread throughout tropical moist forest including areas of disturbed forest. It has been reported from rural gardens and entering villages to prey on rats. Very little is known about the biology of this species. It is, however, clear from a study of museum specimens (Woolley 1994) that breeding occurs throughout the year. The New Guinea Quoll is a top-level predator in New Guinea. Local people report that it spends more time hunting in trees than on the ground.

The New Guinea Quoll is widespread throughout much of New Guinea (Indonesia and Papua New Guinea), but has a patchy distribution across its range. It has a wide elevational range (sea level to 3,600 m) most often occurring 1,000-1,300 m asl; it is absent from the south-western lowlands (Flannery 1995). It is not certain if the species occurs in the Vogelkop region of Papua, although the map is drawn to include that area. The New Guinea Quoll is also found on Yapen Island.

The New Guinea Quoll has been recorded from a number of protected areas, including the YUS Conservation Area on the Huon Peninsula. It is not currently protected by any government legislation and deserves some attention and targeted research as a key predator.