BACKGROUND: The purpose of this study was to compare prospectively two different anesthetic techniques with isoflurane or propofol for postoperative nausea, vomiting and recovery after tonsillectomy in children. METHODS: Sixty children, ASA physical status I, were assigned randomly to one of two groups. In group I, anesthesia was induced with thiopental 5 mg/kg and maintained with isoflurane 1~1.5 vol%. In group P, anesthesia was induced with fentanyl 1 mcg/kg, propofol 2 mg/kg and maintained with propofol infusion 5~10 mg/kg/hr. Both group received vecuronium 0.1 mg/kg for tracheal intubation and were ventilated with 33% O2 in N2O. The time to extubation, time to eye opening, PACU time, incidence and numbers of postoperative nausea and vomiting, and degree of sedation were recorded as well as perioperative complications. RESULTS: There were no significant difference in the duration of anesthesia and PACU time between two groups. The time to extubation and eye opening of group P were significantly shorter than group I (p<0.05). The degree of sedation and incidence of postoperative nausea and vomiting of group P were significantly lower than group I (p<0.05). But the frequency of intraoperative bradycardia was significantly higher in group P than group I (p<0.05). CONCLUSIONS: Propofol-fentanyl anesthesia results in less nausea and vomiting during postoperative period and more rapid recovery compared to isoflurane anesthesia and may be recommended in children undergoing tonsillectomy and adenoidectomy.