The typical adult has brown upperparts and pale underparts, with barring on the undersides of the flight feathers and tail.

The wings are broad with a curved trailing edge, and are held in a shallow V in flight.

A 2008 study based on the geographic isolation and differences in call suggested that this be treated as a full species, Nisaetus kelaarti.

[3] It is a bird of mountain woodland that builds a stick nest in a tree and lays usually a single egg in a clutch.

Despite its relatively modest size, Legge's hawk-eagle is a powerful predator with large talons, like many booted eagles, and is sometimes known to occasionally pursue prey as heavy or heavier than itself.