Background Nasal packing is usually performed to control bleeding after endoscopic sinus surgery (ESS). Although new packing materials have been developed, they still cause pain. This study was designed to evaluate the effect of lidocaine-soaked packs on pain after ESS. Methods A prospective, randomized, double-blind controlled trial was conducted in 63 patients with CRS undergoing ESS. At the conclusion of the operation, 2% lidocaine-soaked biodegradable synthetic polyurethane foam and saline-soaked polyurethane foam were inserted in both nasal cavities of 31 patients and 32 control patients, respectively. The same lidocaine or saline was reapplied into the nasal packs at postoperative 8 hours. Pain was evaluated using a visual analog scale at postoperative 1, 4, 8, 16, 20, and 24 hour(s). The number of gauze that cleaned the blood around the nose was counted. Heart rate, rhythm, and blood pressures were checked preoperatively and postoperatively to evaluate the influence of lidocaine on vital signs. Results Postoperative pain decreased in lidocaine group at all of the postoperative time periods (p < 0.05). Lidocaine reduced postoperative bleeding at postoperative 8 and 24 hours. Changes of blood pressure from preoperative values in the lidocaine group were not different from those in the control group (p > 0.05). Heart rate in the lidocaine group was more stable than that in the control group (p < 0.05). Conclusion Lidocaine-soaked packs significantly reduced postoperative pain without serious changes on vital sign. These findings suggest that topical lidocaine application to nasal packs could be a useful method to reduce pain during the early postoperative period after ESS.