Background: Functional endoscopic sinus surgery (FESS) is a minimallyinvasive, efficient surgical procedure frequently utilized for treating nasal polyposis as well as chronic rhinosinusitis. A clear field is mandatory for surgeons to facilitate the operation; nevertheless, it is linked to complications such as postoperative pain. Objectives: We aimed to determine the impact of infrazygomatic approach sphenopalatine ganglion blockade (SPGB) on hemodynamics, postoperative pain, and the surgical field, in FEES operations. Patients and Methods: This a prospective controlled trial, in 35 patients conducted at Ain Shams University Hospitals, Cairo, Egypt, only submucosal lidocaine was injected after general anesthesia was induced, and one nasal side was randomly selected (left or right) utilizing the closed envelopes method (intranasal injection group). On the other side, the infrazygomatic sphenopalatine ganglion block technique was done (the infrazygomatic block group) then surgical field quality, hemodynamic changes, and postoperative complications (infection or epistaxis) were compared statistically. Results: The surgical field quality was improved more in the infrazygomatic block side, and mean heart rate (HR) and arterial blood pressure demonstrated a statistically substantial decline in the infrazygomatic block intraoperatively but no significant change postoperatively. Additionally, the pain was relieved in the first postoperative 6 hours but statistically no difference was found between the two groups at 12 and 24 hours postoperatively, and also statistics showed no difference between the two sides as regards infection or epistaxis. Conclusion: Infrazygomatic approach of SPGB improves surgical field quality, postoperative pain, and hemodynamic stability in FEES operation.