| Family | Acalyptonotidae Walter, 1911
| 2 7 | Genera Species |
| Family | Amoenacaridae Smith & Cook, 1997
| 1 1 | Genus Species |
| Family | Arenohydracaridae Cook, 1974
| 1 3 | Genus Species |
| Family | Arrenuridae Thor, 1900
| 33 1181 | Genera Species |
| Family | Athienemanniidae Viets, 1922
| 19 57 | Genera Species |
| Family | Bogatiidae Motas & Tanasachi, 1948
| 3 3 | Genera Species |
| Family | Chappuisididae Motas & Tanasachi, 1946
| 5 18 | Genera Species |
| Family | Chapuisididae
| 1 14 | Genus Species |
| Family | Gretacaridae K.O. Viets, 1978
| 0 0 | Genera Species |
| Family | Harpagopalpidae Viets, 1924
| 2 3 | Genera Species |
| Family | Hungarohydracaridae Motas & Tanasachi, 1959
| 4 27 | Genera Species |
| Family | Kantacaridae Imamura, 1959
| 1 1 | Genus Species |
| Family | Krendowskiidae Viets, 1926
| 11 70 | Genera Species |
| Family | Laversiidae Cook, 1955
| 1 1 | Genus Species |
| Family | Mideidae Thor, 1911
| 3 10 | Genera Species |
| Family | Mideopsidae Koenike, 1910
| 54 310 | Genera Species |
| Family | Momoniidae Viets, 1926
| 18 70 | Genera Species |
| Family | Neoacaridae Motas & Tanasachi, 1947 ⇒ Opilioacaridae
| 4 20 | Genera Species |
| Family | Nipponacaridae Imamura, 1959
| 2 3 | Genera Species |
| Family | Nudomideopsidae Smith, 1990 ⇒ Mideopsinae
| 0 0 | Genera Species |
| Family | Uchidastygacaridae Imamura, 1956 ⇒ Uchidastygacarinae
| 1 0 | Genus Species |