A new mite species belonging to family Caligonellidae, Neognathus sinaei sp. nov., from western Iran (Mallayer vicinity, Hamedan province) is described and illustrated base on female and male from soil and litter under Russian olive trees, Elaeagnus angustifolia L.: Elaeagnaceae. A key to adult females of the genus Neognathus is also provided based in original descriptions and literatures.