| Family | Coelopidae Hendel, 1910 Kelp Flies, Seaweed flies | 23 71 | Genera Species |
| Family | Dryomyzidae Schiner, 1862 Dryomyzid flies | 14 101 | Genera Species |
| Family | Helcomyzidae Malloch, 1933 Helcomyzid flies, Kelp flies | 5 26 | Genera Species |
| Family | Helosciomyzidae Griffiths, 1972
| 11 43 | Genera Species |
| Family | Heterocheilidae Mcalpine, 1991 Half-bridge flies | 10 35 | Genera Species |
| Family | Huttoninidae Steyskal, 1965 ⇒ Sciomyzidae Marsh flies, Snail-killing flies | 2 9 | Genera Species |
| Family | Natalimyzidae Barraclough & McAlpine, 2006
| 1 1 | Genus Species |
| Family | Phaeomyiidae Verbeke, 1950 ⇒ Sciomyzidae Marsh flies, Millipede-killing flies, Snail-killing flies | 4 12 | Genera Species |
| Family | Ropalomeridae Linder, 1930 Ropalomerid flies | 14 67 | Genera Species |
| Family | Sciomyzidae Fallen, 1820 Marsh Flies, Marsh fly, Snail-killing flies | 136 1367 | Genera Species |
| Family | Sepsidae Walker, 1833 Black scavenger flies, Ensign flies, Scavenger flies | 71 888 | Genera Species |