Design: A prospective, randomized, double-blinded, placebo controlled protocol. Setting: An academic, tertiary care referral center. Patients: Forty randomly selected children, ages 3 to 13 years, scheduled for adenotonsillectomy without other simultaneous procedures. Intervention: A single, oral dose of dextromethorphan pediatric cough syrup (1 mg/kg) or placebo given 30 minutes before surgery. Main Outcome Measure: Total dose requirement of intravenous morphine within a 6-hour postoperative observation period. Results: During routine postoperative observation, significantly fewer patients in the dextromethorphan group required no intravenous morphine compared with the placebo group (P = .03), Of those children requiring morphine, the mean dose requirement was significantly lower in the dextromethorphan group (P = .02), There was no known drug-related morbidity, Conclusion: Dextromethorphan syrup is a safe, non-narcotic medication that significantly reduced the requirement of intravenous morphine after pediatric adenotonsillectomy, Its routine use in this manner is recommended.