10-18cm. Distinguishing coloration is a black belly with a double row of light dots along the sides of the body. The tail is very stout towards the body and this salamander is one of the largest lungless salamanders.
The benefits of terrestrial life are particularly well illustrated by comparing juvenile mortality rates in various species of dusky salamanders; these decrease steadily from the fully aquatic black-bellied salamander Desmognathus quadramaculatus through to the fully terrestrial pigmy salamander D. wrighti.