Background and objectives: Tonsillectomy is frequently associated with postoperative pain of considerable duration, which is usually accompanied by the substantial consumption of both opioid and non-opioid analgesics. Despite the use of different surgical and anaesthetic techniques in the search for safe and effective post-tonsillectomy pain relief, this problem remains a clinical dilemma. The aim of the current study was to evaluate the potential effects of topically administered ketamine and morphine by an oral rinse into the tonsillar fossae. Methods: In all, 60 children, 15 for each group, aged between 3 and 12yr scheduled for tonsillectomy were randomly assigned to one of four groups. Study drugs were administered to both tonsillar fossae for 5 min. Group K received 0.4 mL (20 mg) ketamine in 10 mL artificial saliva, Group KM received 0.4 mL (20 mg) ketamine + 5 mL (20 mg) 4 parts per thousand morphine aqueous solution in 5 mL artificial saliva, Group M received 5 mL (20 mg) 4 parts per thousand morphine aqueous solution in 5 mL artificial saliva, Group C received only 10 mL artificial saliva. Postoperative pain, nausea, vomiting, sedation and bleeding were evaluated. Results: Pain scores were higher in the control group at arrival in the recovery ward (P < 0.05). Morphine and ketamine groups had longer effective analgesia time than the morphine + ketamine and control groups. The 24-h analgesic consumption was significantly higher in the control group. Conclusion: Topical ketamine and morphine seems to be a safe and easy analgesic approach for decreasing adenotonsillectomy pain.