They have a large round facial disc with silvery white shading to black around the eyes - the face is heavily edged black. Underparts are silvery white with many fine dark grey or sooty black chevrons, particularly on the breast. Lesser Sooty Owls have very short tails. Their eyes are very large with a black Iris. The beak is pale horn.
Toes are pale grey with black talons.
Sexes look similar but the female is usually slightly larger. A piercing downscale whistle, which can sound like a shriek at close quarters. This is similar to the Sooty Owl, but less powerful, and quite often with a slight step in the downward progression of the call. There are also a variety of trills and chirrups associated with breeding. Lesser Sooty Owls hunt mainly small mammals, but also take insects and some birds.