BACKGROUND: In anesthesia for tonsillectomy in children, deep general anesthesia, rapid recovery to consciousness and the return of protective airway reflexes are desirable. This study was designed to estimate the efficacy of TIVA with propofol and fentanyl compared with isoflurane-N2O. METHODS: Forty pediatric patients in ASA class I for tonsillectomy were allocated randomly to either TIVA with propofol and fentanyl (n=20, T) or isoflurane-N2O (n=20, I) group. Anesthesia was induced with propofol 1 mg/kg, fentanyl 3 microgram/kg IV and was maintained by continuous infusion of propofol 6~10 mg/kg/hr, fentanyl 6~10 microgram/kg/hr in T group and was induced with thiopental 5 mg/kg IV and maintained by inhalation of 1.2~2.5 vol% isoflurane in I group. The changes of hemodynamics, recovery time and complications were evaluated. RESULTS: Systolic and diastolic pressure were increased in I group than T group at 1 min after intubation (p<0.05). Heart rate was increased in I group than T group at 1 min after intubation, 1 min and 5 min after incision, changing tube, end of operation and 5 min after end of operation (p<0.05). The recovery time was shorter in T group than I group (p<0.05). Pain on injection was more frequent in T group than I group (p<0.05), and excitatory effect during emergence was more frequent in I group than T group (p<0.05). CONCLUSIONS: TIVA with fentanyl and propofol is better than isoflurane-N2O for anesthesia of tonsillectomy in children in view of small hemodynamic change, early and gentle recovery pattern and side effects.