The gray angelfish has a disk-shaped, compressed body with a large head and small snout. The snout has a mouth at its tip, which is filled with small, bristle-like teeth. The preoperculum has a sizable spine at its corner and a smooth vertical edge. The juveniles have a black body marked with five vertical yellow stripes, three on the head and two on the body. The caudal fin has a black blotch which can be elongated or rectangular. Adults are pale grayish in color and covered in black spots. The head is plain pale gray with a white mouth. The dorsal and anal fins frequently show elongated streamers. The dorsal fin contains 9 spines and 31-33 soft rays, while the anal fin contains 3 spines and 23-25 soft rays. This species attains a maximum total length of 60 centimetres (24 in).