Nacholapithecus kerioi is a large-sized hominoid from the Aka Aiteputh Formation (15 Ma) in Nachola, northern Kenya.(1) While eight large-sized hominoid species dating to the late Early to early Middle Miocene (17-14 Ma) are known in Afro-Arabia and western Eurasia,(2-6) the facial and postcranial anatomy of these apes is poorly known. However, much has been learned of the craniodental and postcranial anatomy of N. kerioi over the last ten years (A list of published specimens is available online, accompanying this article), and it plays a key role in our understanding of hominoid evolution in the Early to Middle Miocene of Africa and Eurasia. Importantly, it bears on the interpretation of the hominoid Morotopithecus bishopi from 20.6 my-old Uganda.(7-10) In the article, we provide information on the anatomy and adaptations of N. kerioi as well as on the site of Nachola, and discuss how our current knowledge of N. kerioi can be incorporated into scenarios of hominoid evolution.