Following study of specimens belonging to Astragalus L. sect. Ammodendron Bunge collected from northeastern Iran, two new species and a new record for Iran are described and reported. Astragalus ayatollahii Nasseh, Joharchi & F. Ghahrem. differs from A. biarjmandicus Podlech & Zarre and A. inchebroonensis Maassoumi in having longer racemes with more flowers, only white trichomes on the calyx, and one pair of leaflets in the lower leaves and two pairs in the upper leaves. Astragalus gonabadensis Nasseh, Joharchi & F. Ghahrem. differs from A. baharensis F. Ghahrem. and A. macrobotrys Bunge in characters of the calyx and legume trichomes. Descriptions, distribution maps, and comparative tables of morphological characteristics for these taxa are presented. In addition, the first record of A. excedens Popov & Kult. in the flora of Iran is reported.