"P. chilensis" can grow to a maximum length of . The dorsal fin has six spines and twenty-eight soft rays, and the anal fin has a single spine and twenty-five soft rays. A specimen caught by Charles Darwin during the "Beagle" voyage was described as being more elongated than "Pinguipes brasilianus", being about six and a half times as long as the body is deep and as having two longitudinal rows of ill-defined spots on the flanks and a larger, dark-coloured, round spot at the base of the caudal fin.