A new species of Eustigmaeus Berlese, 1910 (Acari: Stigmaeidae), E. pseudosetiferus, is described and illustrated from Astragalus sp. (Fabaceae), in Urmia, West Azerbaijan province, Iran. A key to the species of Eustigmaeus known from Iran is provided and E. isfahaniensis is considered as a junior synonym of E. ottavii.
