The species in the Macrouridae are characterised by their large heads[3] which normally have a single barbel on the chin,[4] projecting snouts, and slender bodies that taper to whip-like tails, without an obvious caudal fin[3] but what there is of the caudal fin is often confluent with the posterior dorsal and anal fins.

The body is covered in small scales and if they have a photophore, it is usually on the midline of the abdomen just in front of the anus.

[2] The structure of the skull has been used to show their placing in the Gadiformes, but they differ from the typical cods in that they possess one stout spine in the anterior dorsal fin.

[3] The species in this family are mainly benthopelagic, they are found at depths of 200–2000 m,[4] they occur on the sea bed[3] and have a wide distribution from the Arctic to the Antarctic.

[2] Their bodies are loose in texture rather than firm and they are weak swimmers.