Indo-Pacific: Red Sea and East Africa to the Marquesan and Easter islands, north to southern Japan and the Ogasawara Islands, south to northern Australia and Lord Howe Island. The Hawaiian population has been recognized as a separate subspecies, Conger cinereus marginatus. Whether the species is homogeneous over the rest of its range needs further study.

Brownish grey, yellow below and on fins, median fins with narrow black edge, black patch on lower rear edge of eye and on pectorals. Flanges on upper and lower lips well developed; 2 rows of teeth in jaws, those of outer row larger; closely set and compressed to form cutting edge; 6th infraorbital pore located close behind and slightly above posterior angle of jaw. Dorsal fin begins over middle of appressed pectoral fin. Assumes a pattern of broad dark bands at night.

Solitary species common on reef flats and seagrass beds of shallow lagoons but ranges to depths of 80 m on outer reef slopes.