The Dusky Woodswallow is a smoky deep brown to grey bird. The wings are dark blue grey, edged white, the tail is black with a broad white tip and the underwings are silvery-white. The bill is blue tipped black and the eye is dark brown. Young birds are grey-brown, streaked and mottled buff to cream. This species moves in flocks of 10 to 30 birds, which cluster together to roost.