Abstract Genital papillae of adult mites Hirsutiella zachvatkini (Schluger, 1948) (Trombiculidae), Platytrombidium fasciatum (C. L. Koch, 1836) (Microtrombidiidae) and Teutonia cometes (C. L. Koch, 1837) (Hydrachnidia: Teutoniidae) were examined by means of light-optical and transmission electron microscopy. Three pairs of genital papillae are located in these species on the inner sides of the genital flaps. They are composed of a few electron-lucent and tightly adjoined cells and project by their apical portion into the genital atrium being covered by a modified cuticle. Genital papillae are characterized by vacuolar transport that is most conspicuous in the water mite T. cometes, moderately expressed in Pl. fasciatum and greatly reduced in H. zachvatkini. Genital papillae are thought to remove superfluous water and dissolved waste ions from the organism to provide the necessary salt-water balance for these mites.