The family Amphiliidae has three subfamilies, Amphiliinae, Leptoglanidinae (previously misspelled Leptoglaninae), and Doumeinae.

[3] The Amphiliidae have been previously thought to be a basal taxon in the superfamily Loricarioidea, but some authors place their relationships elsewhere.

The gas bladder is reduced and divided into two lobes surrounded by bony capsules.

[2] The small mouth is located on the underside of the head, and has thick lips bearing several soft lumps (papillae).

The lips, together with tentacles, and with minute spines on the fin rays, enable the fish to grip solid surfaces, so they can hold on in fast-moving streams.