To evaluate the efficacy of Transnasal Sphenopalatine Ganglion Block by Drip Method for Post-Operative Pain Relief in Patients Undergoing Head & Neck Cancer Surgeries Background: A sphenopalatine ganglion block (SPGB) is an interventional procedure to treat chronic head and neck pain. Post-operative pain is a major concern after head & neck cancer surgeries. The primary objective of this study was to find a novel method to decrease post-operative pain and post-operative opioid requirement after head & neck cancer surgeries. Methods: This randomised controlled study divided 100 patients into two groups. Group A received 5 ml of 4 % Lignocaine with 4 mg Dexamethasone and Group B received placebo 5 ml of normal saline. Post-operatively, time from the SPGB to the first rescue analgesia, visual analog scale (VAS) score at 15, 30, 45, 60 & 120 minutes after surgery and difference in total dose of rescue opioid given in 24 hours in both groups were observed and recorded. Results: The time for first rescue analgesia was statistically higher in group A than in group B (P=0.014). Mean VAS score at 15, 30, 45 & 60 minutes were statistically lower in group A than in group B (P=0.001), whereas mean VAS score measured at 120 min, was statistically insignificant. Total opioid dose given during 24 hours in the post-operative period was statistically significant between group A & B (P = 0.004). Duration of surgery and the incidence of complications were statistically insignificant between the two groups. (P = 0.485) Conclusion: SPGB done through the trans-nasal route by drip method provides adequate analgesia in the post-operative period after head & neck surgeries.