Operation-induced acute cerebrospinal fluid (CSF) rhinorrhea is still a great challenge to ENT doctors; we newly developed a transnasal endoscopic “interposition technique” for the repair of leaks, this technique was created from the idea of skull base surgery, “lyodura” as a graft put precisely between dura and skull, with benefit of intracranial pressure, the graft can then be well positioned over the defect site. Three patients with acute cerebrospinal fluid leaks comprise this study. The etiology of CSF leaks in this series included one case of basal encephalocele, and two cases after functional endoscopic sinus surgery. CSF rhinorrhea was immediately documented by nasal sinoscopy under direct vision. Resolution of CSF rhinorrhea was achieved in all patients with the same endoscopic procedure. We consider this newly created endoscopic approach-the interposition technique being an appropriate method in diagnosis and treatment of acute CSD rhinorrhea.