© The Author(s) 2019. Primary spontaneous cerebrospinal fluid (CSF) rhinorrhea is an unusual phenomenon that may occur anywhere along the skull base. However, CSF leaks originating from clival defects are rarely reported in the literature. The majority of reported cases were managed with microscopic techniques, using free grafts. The present study discusses a case of spontaneous CSF rhinorrhea from a clival defect closed with our transnasal operative approach using endoscopic techniques. The skull base defect was successfully managed with an endoscopic binostril approach to create a nasal septal flap pedicled at the sphenopalatine artery, while also preserving the integrity of the nasal septum.