Background and Aim: The major concerns related to the Endoscopic Endonasal Transsphenoidal (EET) surgery for sellar and suprasellar tumors include the risks of post-operative Cerebrospinal Fluid (CSF) leak, leading to morbidity and at times mortality, due to severe meningitis. Time is required to develop possible preventive measures that can reduce the risk of post-operative CSF rhinorrhea. The present study aimed to evaluate the effects of pre-operative CSF diversion by lumbar drainage in EET tumor surgeries on preventing post-operative CSF leak and its effect on the length of hospital stay. Methods and Materials/Patients: We conducted a prospective study on 20 patients with a pituitary tumor that underwent EET surgery between October 2018 and December 2019. Preoperative Lumbar Drain (LD) was inserted after induction in all explored patients. The tumor was excised with continuous intraoperative CSF drainage. Post-operatively, the LD was kept for 3 days and clamped for the next 24 hours. If no evidence of CSF rhinorrhea was present, it was removed. Complications related to CSF drainage, CSF leak, and hospital stays were evaluated. Results: Our study population consisted of 13(65%) men and 7(35%) women, with Mean±SD age of 39.8±10.71 years. The most commonly presented complaint was visual disturbance (60%) and the least common symptom was urinary disturbance (5%). The intra-operative leak was detected in 9(45%) patients, while the post-operative leak was present in only 1(5%) patient. LD blockage significantly contributed to post-operative CSF leak (P=0.001). The Mean±SD hospital stay in the post-operative period was 8.85±3.22 days with 65% of patients having a hospital stay of <7 days. Other post-operative complications (e.g. diabetes insipidus, electrolyte imbalance, and hormonal disturbances) were mainly responsible for prolonged post-operative hospital stay (P=0.001). Conclusion: Pre-operative LD, apart from helping to reduce the incidence of post-operative CSF leak, is not associated with an overall increased post-operative hospital stay.