The pollen size and morphology of 20 Onobrychis Adans. taxa from Turkey were studied using both light and scanning electron microscopy. Of the taxa studied, Onobrychis fallax Freyn & Sint. and Onobrychis elata Boiss. & Balansa showed the smallest size of pollen grains, while the largest were found in Onobrychis aequidentata (Sibth. & Sm.) d'Urv. and Onobrychis viciifolia Scop. The pollens of all taxa studied represent the tricolpate type of pollen and are prolate in shape. The type of exine found in the studied taxa is reticulate (sect. Dendobrychis DC. and sect. Laphobrychis Hand.-Mazz.), suprareticulate (sect. Onobrychis), or microreticulate (sect. Hymenobrychis DC. and sect. Heliobrychis Bunge). A correlation is observed between the pollen size and chromosome number.