BACKGROUND: Strabismus surgery is associated with a high incidence of postoperative nausea and vomiting. Propofol is an anesthetic which has an antiemetic effect. A randomized study was done to compare the efficacy of propofol-fentanyl and propofol-ketorolac anesthesia for strabismus surgery in children. METHODS: Eighty-five children, ASA physical status I or II, for strabismus surgery, were studied. Patients were randomly assigned to one of two groups by picking the envelop. Preanesthetic medication was not given. Fentanyl group received fentanyl 1.5 microgram/kg i.v. and ketorolac group received ketorolac 1 mg/kg, 2 minutes before induction. Atropine was given after that. Anesthesia was induced with propofol 2.4 mg/kg and vecuronium 1 mg/kg and intubation was performed. Anesthesia was maintained with a three-stage infusion technique of propofol (12 mg/kg/hr for 1st 10 minutes, 9 mg/kg/hr for 2nd 10 minutes and 6 mg/kg/hr was followed) with oxygen and nitrous oxide. Ketorolac was injected intramuscularly for preemptive analgesia immediate after induction. The incidence of nausea and vomiting was evaluated for postoperative 48 hours. And also, intraoperative oculocardiac reflex was monitored to compare the difference between two groups. RESULTS: During postoperative 48 hours, fentanyl group and ketorolac group had a similar low incidence of nausea and vomiting (4.2% and 7.0%). There is no significant difference of intraoperative oculocardiac reflex between two groups (45.2% and 30.2%). CONCLUSIONS: Propofol administered to induce and maintain anesthesia with a three-stage infusion technique is equally effective in preventing postoperative nausea and vomiting in propofol-fentanyl and propofol-ketorolac anesthesia for strabismus surgery in children.