Background: Functional endoscopic sinus surgery is a standard procedure for the treatment of chronic sinusitis. This surgery is usually conducted under general anesthesia and it is better to be performed under controlled hypotensive technique to improve surgical field and to decrease the operation time. Routine analgesic treatment is usually based on non-opioid analgesics with rescue opioids. Objective: The aim of this study was to compare opioid free versus opioid based general anesthesia in functional endoscopic sinus surgeries regarding hypotension, surgical field, operation time and postoperative pain. Patients and methods: Patients were divided into 2 equal groups: Group 1: Opioid free group: (Group OFA) 22 participants, Group 2: Opioid based group: (Group OBA) 22 participants. All participants were subjected to medical history taking, complete clinical examination and premedication and routine laboratory investigations. Results: There was no statistical significant difference between the studied groups regarding the mean arterial pressure, oxygen saturation and need for analgesia. Duration of stay in post anesthesia care unit was significantly shorter in OFA group than OBA group. OBA Group was significantly associated with higher VAS score at 6-, 10- and 12-hours postoperatively. Conclusion: OFA provided satisfactory intraoperative analgesia and control of surgery-induced pressor reflexes. Also, the perioperative safety and efficacy of the opioid-free anesthesia techniques provided for functional endoscopic sinus surgeries had good postoperative analgesia and other postrecovery criteria. There is a need for wider-scale comparative studies with large number of patients with long period in multi-center studies to confirm our finding.