Nankeen night herons are short and stocky, medium sized herons with a thick neck. They have a distinctive black cap, a rufous to dull brown (nankeen) back and wings, and a white belly. The underwing is white, the eyes are yellow and the lores and facial skin greenish yellow. The legs and feet range from bright yellow to dusky ochre-yellow. In breeding plumage two to three nuchal plumes raise from the crown, the legs can be bright pink, the lores become blue and the iris red. Male and females are alike except that the female is slightly smaller. The juveniles are heavily spotted and streaked grey-brown. The bill is grey-black with yellowish cutting edges. The eyes are yellow, the bare facial skin is yellow-olive and the legs and feet lime-green to olive-grey.