Purpose <p>Pain is a significant morbidity after functional endoscopic sinus surgery either due to surgery itself or because of nasal packing. Analgesics like opioids are used to alleviate pain but they may be associated with significant side effects. Therefore, there is a need to study topical action of fentanyl.</p> Methods <p>It is a Prospective, Randomized control study. 50 patients with chronic rhinosinusitis were included in the study. Study group was packed with 50 microgram fentanyl soaked merocele. Control group was packed with saline soaked merocele. Post operative pain was assessed at multiple post operative intervals using visual analogue scale and sedative effect was assessed using Ramsay sedation scale. In addition cardiovascular parameters were monitored.</p> Results <p>There was significance difference in pain relief in study group(fentanyl) when compared to control group (normal saline) at post operative 0hr, 4hr.10hr, 24hr, 48hr with p&lt;0.05. There was no significant difference in pain relief among two groups during pack removal with p=0.112. Mean pain score in test group at 0 hour was 5.32, while in control group was 6.84. Mean pain score in study group at pack removal was 7.24, in control group was 7.56. There was no significant difference in Ramsay sedation scores at different post operative intervals. There was no significant difference in cardiovascular parameters among both groups(p&lt;0.05). No significant side effects were reported.</p>