Background: Functional endoscopic sinus surgery (FESS) is a widespread operation that allows good inspection, illumination and enhances surgical procedures. However, excessive bleeding has been notified for FESS done under general anesthesia (GA) resulting from reduced clarity. Controlled hypotension is usually used to constrict intraoperative blood loss, but it may cause varied dilemmas. Objective: This study aimed to evaluate the safety and efficacy of trans-nasal sphenopalatine ganglion block (SPGB) in optimizing surgical conditions and reducing the anesthetics used during FESS. Patients and methods: Aprospective controlled randomized trial was conducted on one hundred adult patients with ASA physical status I & II. They aged from 18 to 60 years and were scheduled for FESS with or without septoplasty in Menoufia University Hospital. After induction of GA, patients were randomly allocated into two equal groups (50 patients each). In group 1 (block group)patients received bilateral SPGB with 1.5 ml of 0.5% bupivacaine. In group 2 (control group) patients received bilateral SPGB using 1.5 ml of normal saline. Both the anesthetist and the surgeon were blinded to the drug being administered. Hemodynamic parameters, surgical field visibility, anesthetic consumption, use of adjuvant drugs for hypotensive anesthesia, operative time, postoperative pain analgesic usages, and technique-related complications were observed. Results: The heart rate, mean arterial blood pressure, bleeding, surgical duration, and VAS were significantly improved in the SPGB group than in the control group. Conclusion: In our study, SPBG block showed hemodynamic stability, less blood loss, lower anesthetic and analgesic consumptions, and improved surgical field visualization, as well as it reduced postoperative pain and complications.