Astragalus kamarinensis C. Brullo, Brullo, Giusso, Miniss. & Sciandr. sp. nova (Fabaceae) is described and illustrated from Sicily. It grows exclusively on sandy soils, near the ruins of Kamarina, located in the southern part of Sicily. Morphologically, it shows close relationships with A. Stella, A. raphaelis and A. tribuloides, all belonging to A. sect. Sesamei. Several morphological features, chiefly regarding the flowers, legumes and seeds, as well as the micromorphology of the pod indumentum and seed coat, allow to well distinguish this species from the other taxa in the section. A phenetic analysis based on the morphological characters supports our taxonomic conclusions.