Alyssum hezarmasjedense Kavousi & Nazary (Brassicaceae) is described as a new species from Khorassan Province in northeastern Iran. The morphological characters of the sepals being dimorphic and appearing connate, with the inner surface indument, support the placement of the new species in Alyssum L. sect. Gamosepalum (Hausskn.) Dudley. The new species is closely related to A. misirdalianum Orcan & Binzet.