Background Many surgeons have practiced endoscopic repair of cerebrospinal fluid (CSF) rhinorrhea in past decade and have gained popularity. There are several centers that adopt endoscopic repair as a first-line treatment for CSF rhinorrhea with high success rate. Objective The aim of this study was to detect the role of the transnasal endoscopic approach in the repair of the CSF rhinorrhea and assess its surgical outcome. Patients and methods A prospective study of 40 patients having CSF rhinorrhea was conducted. All patients were treated with endoscopic repair for CSF rhinorrhea at Neurosurgery Departments of Al-Azher University and specialized Hospital of Otorhinolaryngology and Neurosurgery from January 2016 to January 2018. The majority of them were men. The defects were closed in multilayers using fascia lata, septal cartilage graft, and nasal mucosa in most patients. Results The left cribriform plate area was found as the most common site of CSF leak. The spontaneous CSF leak was the most common cause of CSF rhinorrhea in this study, and post-traumatic (iatrogenic) CSF leak was the second most common cause. Our success rate of the first attempt at endoscopic repair was 90%, and in the second attempt was 97.5%. The causes that lead to recurrence of leak were large defect, failure of localization of the defect, and comorbid conditions such as bone erosion and chronic cough that developed postoperatively. Conclusion Endoscopic endonasal approach is a safe and effective way to repair CSF leaks of different causes. Multilayer repair technique is safe and effective, with low complications and preservation of nasal and neurological functions. However, more studies and long series are recommended.