Generally, they are small to medium, densely populated, coloured flies.

The superfamily has three synapomorphies (features present in all members due to a common ancestor): convergent postocellar bristles, an abbreviated anal vein in the wing, and fusion of male abdominal tergites 7 and 8.

[2] Within the superfamily, Celyphidae can be distinguished from other families by their scutellum, which is shiny, enlarged and covers most of the abdomen, similar to a beetle's elytra.

[3] Lauxaniidae are yellowish-brown or black, usually have iridescent reddish/purplish or greenish eyes, and the wings are sometimes patterned.

[3][5] A 2017 phylogenetic analysis using mitochondrial genomes confirmed the monophyly of Lauxaniidae and of Celyphidae, and that these two families are sister groups.