PURPOSE: Postoperative pain control following adenotonsillectomy in the pediatric population poses a great challenge to care providers. Multi-modal pain management regimes including NSAIDs such as intraoperative ketorolac usage has been purposed for many years. However, the effectiveness of ketorolac to reduce post-tonsillectomy pain and opioid-related side effects is controversial. The study was to evaluate the opioid-sparing effect of an intraoperative intravenous single dose of ketorolac in children undergoing adenotonsillectomy. We also assessed the effectiveness of perioperative ketorolac on alleviating the common adverse effects of opioid usage. METHODS: With IRB approval, a total of 142 pediatric patients aged between 3 and 12 years undergoing elective adenotonsillectomy were randomized to receive either placebo or 0.5 mg/kg ketorolac intraoperatively with other pain management remaining the same. The primary outcomes were postoperative pain scores and postoperative rescue pain medication usage. Common postoperative anesthesia-related complications such as nausea, vomiting and postoperative rebleeding were assessed. RESULTS: We found that ketorolac usage decreased the overall postoperative pain scores significantly (Max FLACC score 4.3 ± 2.6 for ketorolac vs. 5.9 ± 3.0 for placebo). However, intraoperative single-dose ketorolac administration did not reduce postoperative rescue opioid usage, nor decrease the rates of postoperative nausea and vomiting. We did not observe significant postoperative bleeding or other complications associated with ketorolac usage. CONCLUSIONS: While intraoperative ketorolac usage reduces the overall postoperative pain score, it does not decrease the postoperative opioid consumption in our current practice regime. Ketorolac may be a good multi-modal pain management adjunct without increased postoperative complications such as rebleeding.