Mawson's dragonfish has a slender, naked body with the only scales being in the two lateral lines, the upper lateral line is wholly made up of perforated scales. There is a flattened ridge on the operculum which divides towards the margin. They have a thin band of conical teeth in the jaws. The dorsal fin has 61-66 soft rays while the anal fin has 36-38. In alcohol the overall colour is brown with darker saddles and bars, the median fins are darker than the pectoral and pelvic fins. This species grows to a length of standard length.