On New Guinea, the Long-nosed Echymipera is found in primary lowland tropical moist forest and grassland adjacent to closed forest. The species is considered to be intolerant to habitat disturbance. In Australia, it is known from mesophyll vine forest, notophyll vine forest, gallery forest and coastal closed heath near to closed forest (Gordon 2008).
On Cape York Peninsula in Australia the diet appears to be more frugivorous, and pouch life may be about 2 weeks longer, than in other Australian peramelid bandicoots (Shevill and Johnson 2008). Otherwise it is similar to the Australian bandicoots in being an opportunistic omnivore with a relatively high reproductive rate.

This widely distributed species ranges from the islands of Misool, Yapen, the Aru Islands, and Kai Islands (all Indonesia); across the island of New Guinea (Indonesia and Papua New Guinea); to the D'Entrecasteaux Islands (Goodenough, Fergusson, and Normanby) of Papua New Guinea and the Cape York Peninsula of Queensland, Australia, in the south. It ranges from sea level to 2,100 m, but almost always below 1,200 m asl. In Queensland it occurs from sea level to 800 m asl.

The Long-nosed Echymipera occurs in several protected areas. Further studies are needed into the distribution, abundance, natural history, and threats to this species.