Partula grisea is a tree snail endemic to the Bismarck Archipelago, where it has an extensive multi-island distribution. This species has a confused taxonomic history, which has limited past assessments. However, all populations ascribed to the species appear to be tolerant of current threats. Therefore, it is assessed as Least Concern.

Rensch (1937) recorded this species from multiple islands: Manus, Mussau/St. Matthias, New Hanover/Neu-Hannover, New Ireland/Neu-Mecklenberg, Mahur, Lihir, 12 Duke of York Islands/Neu-Lauenburg, Watom/Vuatom, (Lolobau), and New Britain/Neu-Pommern. Dell (1955) recorded it in from Nissan Island. O'Foighil et al. (2011) sampled it in 2005 from three locations close to the town of Pomio on the island of New Britain. Therefore, it can be concluded that this species has an extensive multi-island distribution throughout the Bismarck Archipelago where it occurs on both high and low islands. 

There are insufficient data on population size or trends for this species. The only records in the past 50 years are from around the town of Pomio, New Britain (O'Foighil et al. 2011). The species may be locally abundant in small pockets around some villages, such as Marmar and Ulege villages on New Britain, but is not present in native forest.

This is an arboreal snail species. Atypically for a partulid, it occurs on low islands and also around coastal villages on large high islands, but not in the native interior forest. O'Foighil et al. (2011) proposed that this distribution pattern strongly implicates human introduction as the dispersive mechanism. 

There is no information about any threats to this species. Potential threats include land use changes and human developments, as well as local use for handicrafts.

Many partulids were used in necklace making but no trade was recorded in this species.

No species-specific measures are known for this species. This species has only been recorded from human made habitats. Further survey work within its known range and elsewhere in the southwestern most part of the range is needed to establish the natural range and habitat for this species.