Elongated, compressed body that is usually reddish brown. At times mottled with black or pale grey, with a black streak above the maxilla.
It looks like Mycteroperca fusca (Island grouper). This species can be distinguished by its darker, greyish-brown colouration and a more restricted range around the eastern Atlantic islands. It shares the elongated body shape and serrated preopercle margin characteristic of Mycteroperca rubra, from which it is otherwise almost indistinguishable without internal examination.