Javan hawk-eagles have a dark brown back and chestnut colouring along the sides of the head and the nape; the throat is cream-coloured with a dark stripe. The crest is held almost vertically and is black tipped with white. The wings are dark brown while the long tail is grey-brown with four black bands, the subterminal band being the widest. Underparts are white with rufous barring. The eyes and feet are yellow and the cere is grey.

Juveniles are similar to adults but have plainer underparts and duller colouring on the head. The tail, instead of the four found in adults, has five black bars. The eyes are blue-grey and turn yellow during their second year.

Their call is a high-pitched whistle.