Habitat loss through deforestation is the greatest threat to Bubo vosseleri.
Bubo vosseleri is endemic to the Usambara Mountains in north-east Tanzania, where until recently it was believed to be montane, all records coming from 900--1,500 m, however records from three lowland patches suggest that the species may be commoner in such habitat, although this is extremely limited in extent and even more at risk of destruction than the montane forest. Possibly however, these birds were cold-season altitudinal migrants.
Numbers of Bubo vosseleri are thought to lie between 200 and 1,000 birds. Bubo vosseleri is listed as "Vulnerable by the IUCN Red List.