A small, dark forest hornbill found predominantly in primary forest subcanopy, where it is often seen in areas with lots of vines. This species is unique in its overall dark coloration and its broad white eyebrow that extends to the back of the head. The only similarly-sized forest hornbill in its range is the more reddish Red-billed Dwarf Hornbill, but Black Dwarf Hornbill has a less well-defined border between the dark chest and white belly, and only Black Dwarf Hornbill has the broad white eyebrow behind the eye. Voice is a repetitive “yep yep yep yep” that can be repeated at length, sometimes accompanied with a howl.