© 2017, © by the Society of Vertebrate Paleontology. The Guadix-Baza Basin (Granada, southern Spain) represents one of the best continental records from the late Miocene to the middle Pleistocene in western Europe, but stratigraphic gaps are present in the early Pliocene due to the scarcity of sites from this time. In this article, rodent fossils from the locality of Baza-1 are described, providing new information on a time interval that was previously poorly known. The assemblage includes representatives of the genera Ruscinomys, Apocricetus, Stephanomys, Apodemus, Castillomys, Paraethomys, Occitanomys, Eliomys, Debruijnimys, and Trilophomys, an association that indicates an early Ruscinian age (MN14). A paleoecological analysis indicates that the Guadix-Baza Basin landscape during the early Pliocene was dominated by open herbaceous habitat under warm and dry climatic conditions. Our results contribute to the continuity of the stratigraphic record from the Betic Mountain range. Citation for this article: Piñero, P., J. Agustí, O. Oms, H.-A. Blain, C. Laplana, S. Ros-Montoya, and B. Martínez-Navarro. 2017. Rodents from Baza-1 (Guadix-Baza Basin, southeast Spain): filling the gap of the early Pliocene succession in the Betics. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2017.1338294.